diff --git a/web/app/dashboard/knowledge/_components/knowledge-directory-panel.tsx b/web/app/dashboard/knowledge/_components/knowledge-directory-panel.tsx
index 088a4bd..c0d7ec8 100644
--- a/web/app/dashboard/knowledge/_components/knowledge-directory-panel.tsx
+++ b/web/app/dashboard/knowledge/_components/knowledge-directory-panel.tsx
@@ -6,6 +6,7 @@ import {
   MouseSensor,
   TouchSensor,
   closestCenter,
+  useDroppable,
   useSensor,
   useSensors,
   type DragEndEvent,
@@ -61,7 +62,11 @@ import {
 } from "@/lib/api/admin";
 import { useI18n } from "@/i18n/provider";
 import { cn } from "@/lib/utils";
-import { findDirectoryParentId, moveDirectoryWithinParent } from "./knowledge-directory-sort";
+import {
+  findDirectoryParentId,
+  moveDirectoryToParent,
+  moveDirectoryWithinParent,
+} from "./knowledge-directory-sort";
 
 type KnowledgeDirectoryPanelProps = {
   knowledgeBaseId: number;
@@ -84,6 +89,7 @@ const DIRECTORY_PANEL_WIDTH_STORAGE_KEY = "knowledge-directory-panel-width";
 const DIRECTORY_PANEL_MIN_WIDTH = 180;
 const DIRECTORY_PANEL_MAX_WIDTH = 360;
 const DIRECTORY_PANEL_DEFAULT_WIDTH = 224;
+const ROOT_DIRECTORY_DROP_ID = "knowledge-directory-root";
 
 function rootDirectoryOptions(items: KnowledgeDirectory[]): DirectoryOption[] {
   return items.map((item) => ({ value: String(item.id), label: item.name }));
@@ -305,14 +311,29 @@ export function KnowledgeDirectoryPanel({
       return;
     }
     const activeId = Number(active.id);
+    if (!Number.isFinite(activeId)) {
+      return;
+    }
+    if (over.id === ROOT_DIRECTORY_DROP_ID) {
+      await handleDirectoryMoveToParent(activeId, 0);
+      return;
+    }
     const overId = Number(over.id);
-    if (!Number.isFinite(activeId) || !Number.isFinite(overId)) {
+    if (!Number.isFinite(overId)) {
       return;
     }
 
     const activeParentId = findDirectoryParentId(directories, activeId);
     const overParentId = findDirectoryParentId(directories, overId);
-    if (activeParentId === null || overParentId === null || activeParentId !== overParentId) {
+    if (activeParentId === null || overParentId === null) {
+      return;
+    }
+    if (activeParentId !== overParentId) {
+      await handleDirectoryMoveToParent(activeId, overId);
+      return;
+    }
+    if (activeParentId === 0 && overParentId === 0 && event.delta.x > 24) {
+      await handleDirectoryMoveToParent(activeId, overId);
       return;
     }
 
@@ -341,6 +362,42 @@ export function KnowledgeDirectoryPanel({
     }
   }
 
+  async function handleDirectoryMoveToParent(activeId: number, targetParentId: number) {
+    const previousDirectories = directories;
+    const moved = moveDirectoryToParent(previousDirectories, activeId, targetParentId);
+    if (!moved.changed || !moved.item) {
+      return;
+    }
+
+    setDirectories(moved.items);
+    if (moved.parentId > 0) {
+      setExpandedIds((current) => new Set(current).add(moved.parentId));
+    }
+    setSorting(true);
+    try {
+      await updateKnowledgeDirectory({
+        id: moved.item.id,
+        knowledgeBaseId,
+        parentId: moved.parentId,
+        name: moved.item.name,
+        remark: moved.item.remark || "",
+      });
+      await updateKnowledgeDirectorySort({
+        knowledgeBaseId,
+        parentId: moved.parentId,
+        ids: moved.orderedIds,
+      });
+      toast.success(t("knowledge.directoryMoved"));
+      await loadDirectories();
+      onChanged?.();
+    } catch (error) {
+      setDirectories(previousDirectories);
+      toast.error(error instanceof Error ? error.message : t("knowledge.directoryMoveFailed"));
+    } finally {
+      setSorting(false);
+    }
+  }
+
   return (
     <>
       <div
@@ -368,17 +425,16 @@ export function KnowledgeDirectoryPanel({
               selected={selectedDirectoryId === null}
               onClick={() => onSelectDirectory(null)}
             />
-            <DirectoryStaticRow
-              icon={<FolderIcon className="size-4 text-muted-foreground" />}
-              label={t("knowledge.rootContent")}
-              selected={selectedDirectoryId === 0}
-              onClick={() => onSelectDirectory(0)}
-            />
             <DndContext
               sensors={sensors}
               collisionDetection={closestCenter}
               onDragEnd={(event) => void handleDirectoryDragEnd(event)}
             >
+              <RootDirectoryRow
+                selected={selectedDirectoryId === 0}
+                onClick={() => onSelectDirectory(0)}
+                t={t}
+              />
               <SortableContext
                 items={directories.map((item) => item.id)}
                 strategy={verticalListSortingStrategy}
@@ -490,16 +546,18 @@ type DirectoryStaticRowProps = {
   icon: ReactNode;
   label: string;
   selected: boolean;
+  draggingOver?: boolean;
   onClick: () => void;
 };
 
-function DirectoryStaticRow({ icon, label, selected, onClick }: DirectoryStaticRowProps) {
+function DirectoryStaticRow({ icon, label, selected, draggingOver, onClick }: DirectoryStaticRowProps) {
   return (
     <button
       type="button"
       className={cn(
         "flex w-full items-center gap-1 px-2 py-1.5 text-left text-sm hover:bg-accent",
         selected && "bg-accent text-accent-foreground",
+        draggingOver && "bg-primary/10 text-accent-foreground",
       )}
       onClick={onClick}
     >
@@ -510,6 +568,30 @@ function DirectoryStaticRow({ icon, label, selected, onClick }: DirectoryStaticR
   );
 }
 
+type RootDirectoryRowProps = {
+  selected: boolean;
+  onClick: () => void;
+  t: TFunction;
+};
+
+function RootDirectoryRow({ selected, onClick, t }: RootDirectoryRowProps) {
+  const { isOver, setNodeRef } = useDroppable({
+    id: ROOT_DIRECTORY_DROP_ID,
+  });
+
+  return (
+    <div ref={setNodeRef}>
+      <DirectoryStaticRow
+        icon={<FolderIcon className="size-4 text-muted-foreground" />}
+        label={t("knowledge.rootContent")}
+        selected={selected}
+        draggingOver={isOver}
+        onClick={onClick}
+      />
+    </div>
+  );
+}
+
 type DirectoryNodeProps = {
   item: KnowledgeDirectory;
   depth: number;
diff --git a/web/app/dashboard/knowledge/_components/knowledge-directory-sort.test.mjs b/web/app/dashboard/knowledge/_components/knowledge-directory-sort.test.mjs
index 2f49e50..bb49100 100644
--- a/web/app/dashboard/knowledge/_components/knowledge-directory-sort.test.mjs
+++ b/web/app/dashboard/knowledge/_components/knowledge-directory-sort.test.mjs
@@ -73,4 +73,48 @@ describe("knowledge directory sorting", () => {
     assert.equal(next.items, tree)
     assert.deepEqual(plain(next.orderedIds), [])
   })
+
+  it("moves a child directory back to the root level", async () => {
+    const { moveDirectoryToParent } = await loadModule()
+
+    const next = moveDirectoryToParent(tree, 11, 0)
+
+    assert.equal(next.changed, true)
+    assert.equal(next.parentId, 0)
+    assert.equal(next.item?.parentId, 0)
+    assert.deepEqual(plain(next.items).map((item) => item.id), [1, 2, 3, 11])
+    assert.deepEqual(plain(next.items[0].children).map((item) => item.id), [12])
+    assert.deepEqual(plain(next.orderedIds), [1, 2, 3, 11])
+  })
+
+  it("moves a root directory without children under another root directory", async () => {
+    const { moveDirectoryToParent } = await loadModule()
+
+    const next = moveDirectoryToParent(tree, 3, 2)
+
+    assert.equal(next.changed, true)
+    assert.equal(next.parentId, 2)
+    assert.equal(next.item?.parentId, 2)
+    assert.deepEqual(plain(next.items).map((item) => item.id), [1, 2])
+    assert.deepEqual(plain(next.items[1].children).map((item) => item.id), [3])
+    assert.deepEqual(plain(next.orderedIds), [3])
+  })
+
+  it("rejects moving a directory with children under another directory", async () => {
+    const { moveDirectoryToParent } = await loadModule()
+
+    const next = moveDirectoryToParent(tree, 1, 2)
+
+    assert.equal(next.changed, false)
+    assert.equal(next.items, tree)
+  })
+
+  it("rejects moving a directory under a child directory", async () => {
+    const { moveDirectoryToParent } = await loadModule()
+
+    const next = moveDirectoryToParent(tree, 3, 11)
+
+    assert.equal(next.changed, false)
+    assert.equal(next.items, tree)
+  })
 })
diff --git a/web/app/dashboard/knowledge/_components/knowledge-directory-sort.ts b/web/app/dashboard/knowledge/_components/knowledge-directory-sort.ts
index 549a136..df1686b 100644
--- a/web/app/dashboard/knowledge/_components/knowledge-directory-sort.ts
+++ b/web/app/dashboard/knowledge/_components/knowledge-directory-sort.ts
@@ -11,6 +11,11 @@ export type MoveDirectoryResult<T extends SortableKnowledgeDirectory> = {
   orderedIds: number[]
 }
 
+export type MoveDirectoryToParentResult<T extends SortableKnowledgeDirectory> =
+  MoveDirectoryResult<T> & {
+    item: T | null
+  }
+
 function arrayMove<T>(items: T[], fromIndex: number, toIndex: number) {
   const next = [...items]
   const [item] = next.splice(fromIndex, 1)
@@ -34,6 +39,64 @@ export function findDirectoryParentId<T extends SortableKnowledgeDirectory>(
   return null
 }
 
+export function findDirectory<T extends SortableKnowledgeDirectory>(
+  items: T[],
+  id: number,
+): T | null {
+  for (const item of items) {
+    if (item.id === id) {
+      return item
+    }
+    const child = findDirectory(item.children as T[] | undefined ?? [], id)
+    if (child !== null) {
+      return child
+    }
+  }
+  return null
+}
+
+export function moveDirectoryToParent<T extends SortableKnowledgeDirectory>(
+  items: T[],
+  activeId: number,
+  targetParentId: number,
+): MoveDirectoryToParentResult<T> {
+  if (activeId === targetParentId) {
+    return unchangedParentMove(items, targetParentId)
+  }
+
+  const activeItem = findDirectory(items, activeId)
+  const activeParentId = findDirectoryParentId(items, activeId)
+  if (!activeItem || activeParentId === null || activeParentId === targetParentId) {
+    return unchangedParentMove(items, targetParentId)
+  }
+
+  if (targetParentId > 0) {
+    const targetParent = findDirectory(items, targetParentId)
+    if (!targetParent || targetParent.parentId !== 0 || (activeItem.children?.length ?? 0) > 0) {
+      return unchangedParentMove(items, targetParentId)
+    }
+  }
+
+  const removed = removeDirectory(items, activeId)
+  if (!removed.item) {
+    return unchangedParentMove(items, targetParentId)
+  }
+
+  const movedItem = { ...removed.item, parentId: targetParentId } as T
+  const appended = appendDirectoryToParent(removed.items, targetParentId, movedItem)
+  if (!appended.changed) {
+    return unchangedParentMove(items, targetParentId)
+  }
+
+  return {
+    items: appended.items,
+    changed: true,
+    parentId: targetParentId,
+    orderedIds: appended.siblings.map((item) => item.id),
+    item: movedItem,
+  }
+}
+
 export function moveDirectoryWithinParent<T extends SortableKnowledgeDirectory>(
   items: T[],
   parentId: number,
@@ -76,6 +139,78 @@ export function moveDirectoryWithinParent<T extends SortableKnowledgeDirectory>(
   }
 }
 
+function unchangedParentMove<T extends SortableKnowledgeDirectory>(
+  items: T[],
+  parentId: number,
+): MoveDirectoryToParentResult<T> {
+  return { items, changed: false, parentId, orderedIds: [], item: null }
+}
+
+function removeDirectory<T extends SortableKnowledgeDirectory>(
+  items: T[],
+  id: number,
+): { items: T[]; item: T | null } {
+  let removedItem: T | null = null
+  const nextItems: T[] = []
+
+  for (const item of items) {
+    if (item.id === id) {
+      removedItem = item
+      continue
+    }
+    if (item.children?.length) {
+      const removed = removeDirectory(item.children as T[], id)
+      if (removed.item) {
+        removedItem = removed.item
+        nextItems.push({ ...item, children: removed.items } as T)
+        continue
+      }
+    }
+    nextItems.push(item)
+  }
+
+  return {
+    items: removedItem ? nextItems : items,
+    item: removedItem,
+  }
+}
+
+function appendDirectoryToParent<T extends SortableKnowledgeDirectory>(
+  items: T[],
+  parentId: number,
+  item: T,
+): { items: T[]; changed: boolean; siblings: T[] } {
+  if (parentId === 0) {
+    const siblings = [...items, item]
+    return { items: siblings, changed: true, siblings }
+  }
+
+  let changed = false
+  let siblings: T[] = []
+  const nextItems = items.map((current) => {
+    if (current.id === parentId) {
+      siblings = [...((current.children as T[] | undefined) ?? []), item]
+      changed = true
+      return { ...current, children: siblings } as T
+    }
+    if (current.children?.length) {
+      const appended = appendDirectoryToParent(current.children as T[], parentId, item)
+      if (appended.changed) {
+        changed = true
+        siblings = appended.siblings
+        return { ...current, children: appended.items } as T
+      }
+    }
+    return current
+  })
+
+  return {
+    items: changed ? nextItems : items,
+    changed,
+    siblings,
+  }
+}
+
 function moveSiblingList<T extends SortableKnowledgeDirectory>(
   items: T[],
   parentId: number,
diff --git a/web/messages/en-US.json b/web/messages/en-US.json
index 7a5884e..a6e35e6 100644
--- a/web/messages/en-US.json
+++ b/web/messages/en-US.json
@@ -1804,6 +1804,8 @@
     "directoryDeleted": "Directory deleted: {name}",
     "directorySaveFailed": "Could not save the directory.",
     "directoryDeleteFailed": "Could not delete the directory.",
+    "directoryMoved": "Directory moved.",
+    "directoryMoveFailed": "Could not move directory.",
     "directorySortUpdated": "Directory order updated.",
     "directorySortUpdateFailed": "Could not update directory order.",
     "directoryNameRequired": "Directory name is required.",
diff --git a/web/messages/zh-CN.json b/web/messages/zh-CN.json
index 16613cd..9b8ea39 100644
--- a/web/messages/zh-CN.json
+++ b/web/messages/zh-CN.json
@@ -1804,6 +1804,8 @@
     "directoryDeleted": "已删除目录：{name}",
     "directorySaveFailed": "保存目录失败",
     "directoryDeleteFailed": "删除目录失败",
+    "directoryMoved": "目录已移动",
+    "directoryMoveFailed": "移动目录失败",
     "directorySortUpdated": "目录排序已更新",
     "directorySortUpdateFailed": "更新目录排序失败",
     "directoryNameRequired": "目录名称不能为空",