diff --git a/docs/INDEX.md b/docs/INDEX.md
index 9db1351..cb0183f 100644
--- a/docs/INDEX.md
+++ b/docs/INDEX.md
@@ -54,7 +54,7 @@ packages/
 | 文件 | 关键导出 | 职责 |
 |---|---|---|
 | `src/ipc-channels.ts` | `CHANNEL_TABLE`、`ch`、`IpcChannels`、`InvokeApi`/`InvokeHandlers` | **IPC invoke 通道单一事实源**：key（=PiApi 方法名）→ 通道字符串 + args/ret 类型；按域子表（SESSION/SETTINGS/PACKAGES/APP/LAN/EXTENSION_DIALOG/UI_PLUGINS）；EVENT_CHANNELS 段 = main→renderer 单向事件（PascalCase 手写） |
-| `src/ipc.ts` | `PiApi` | `window.pi` 完整类型：invoke 成员由 `InvokeApi<CHANNEL_TABLE>` 推导 + 订阅 on* ×11 与 `platform` 手写 |
+| `src/ipc.ts` | `PiApi` | `window.pi` 完整类型：invoke 成员由 `InvokeApi<CHANNEL_TABLE>` 推导；订阅 on* ×11、`platform` 与 preload 原生文件路径桥 `getPathForFile` 手写 |
 | `src/session.ts` | `SessionMeta`、`SessionStats`、`AvailableModel`（可选 `thinkingLevels`/`imageInput`，缺省 fail-open）、`SessionEvent`、`SessionMessage`、`UiState`、`PermissionRequest`、`PermissionMode`（default/fullAccess）、`TrustRequest`、`LoadedResources` 等 | 会话/事件跨进程类型。`SessionEvent` = pi `AgentSessionEvent` ∪ Percho 自有 UI 事件（`subagent_mutex`/`stream_guard_tripped`，不进 trace）；`SessionMessage` union：user/assistant（均带 `entryId` 供 fork/撤回；user 专属 `skill`/`sourceText`）+ `role:"image"`（show_image 回放）+ `role:"subagent"` |
 | `src/transcript/` | `reduceEvent`、`messagesToUIMessages`、`buildChatRows`、`deriveTurnChanges`、`deriveTurnTimings` | **UI 消息状态机（桌面与 lan-web 共用同一份）**：`types`（UIMessage/StreamingState 等）、`helpers`（事件载荷解析）、`reducer`（pi 事件 → UI 状态）、`mapping`（历史回放）、`parse-patch`（unified diff 结构化解析）、`turn-files`（按轮聚合文件变更）、`turn-timings`（按轮计时派生 + runEndedAt 定格）、`chat-rows`（行序列分组 + 轮末行定位规则；入参 `ChatRowsInput` 四字段收窄）、`llm-errors`（LLM 错误轮判定 live/replay 共用）、`meta-summary`（工具语义分类统计） |
 | `src/errors.ts` | `UiError`、`classifyLlmError`、`buildLlmUiError`、`buildStreamGuardUiError`、`DETAIL_MAX_LENGTH` | 统一报错信封：错误卡数据源（live reducer / 历史回放 mapping / Composer 内联 / LAN 共用）；`classifyLlmError` 按 401/429/context/网络模式分类，误判只影响标题措辞 |
diff --git a/packages/desktop/src/preload/index.ts b/packages/desktop/src/preload/index.ts
index b7d5d20..92e97fe 100644
--- a/packages/desktop/src/preload/index.ts
+++ b/packages/desktop/src/preload/index.ts
@@ -15,7 +15,7 @@ import {
 	type UiPluginsEventPayload,
 	type UpdateState,
 } from "@percho/shared";
-import { contextBridge, ipcRenderer } from "electron";
+import { contextBridge, ipcRenderer, webUtils } from "electron";
 
 /** 事件订阅包装：ipcRenderer.on + 返回退订函数（removeListener），payload 透传 */
 function makeSubscription<T>(channel: string): (cb: (payload: T) => void) => () => void {
@@ -36,6 +36,7 @@ const invokeApi = Object.fromEntries(
 
 const api: PiApi = {
 	platform: process.platform,
+	getPathForFile: (file) => webUtils.getPathForFile(file as Parameters<typeof webUtils.getPathForFile>[0]),
 	...invokeApi,
 	onProviderLoginEvent: makeSubscription<LoginEventPayload>(IpcChannels.SettingsLoginEvent),
 	onUiPluginsEvent: makeSubscription<UiPluginsEventPayload>(IpcChannels.UiPluginsEvent),
diff --git a/packages/desktop/src/renderer/src/components/composer/Composer.tsx b/packages/desktop/src/renderer/src/components/composer/Composer.tsx
index b84ed98..50d8973 100644
--- a/packages/desktop/src/renderer/src/components/composer/Composer.tsx
+++ b/packages/desktop/src/renderer/src/components/composer/Composer.tsx
@@ -1,5 +1,6 @@
 import type { ImageInput } from "@percho/shared";
-import { useEffect, useRef, useState } from "react";
+import { useCallback, useEffect, useRef, useState } from "react";
+import { getPi } from "../../api";
 import { useActiveModelInfo, useSessionReadOnly } from "../../hooks/use-session-state";
 import { useT } from "../../i18n";
 import { RegionHost } from "../../plugins/RegionHost";
@@ -13,6 +14,7 @@ import { ArrowUpIcon, PencilIcon, PlusIcon, StopIcon } from "../icons";
 import { AtMenu } from "./AtMenu";
 import { AttachmentChip } from "./AttachmentChip";
 import { ContextRing } from "./ContextRing";
+import { resolveDroppedFilePaths } from "./drop-files";
 import { ImageTray } from "./ImageTray";
 import { ModelPicker } from "./ModelPicker";
 import { PermissionPicker } from "./PermissionPicker";
@@ -68,6 +70,16 @@ export function Composer({ centered = false }: { centered?: boolean }) {
 			attachments: typeof updater === "function" ? updater(d.attachments) : updater,
 		}));
 	};
+	const appendAttachments = useCallback(
+		(paths: string[]) => {
+			if (paths.length === 0) return;
+			updateDraft(draftKey, (d) => ({
+				...d,
+				attachments: [...new Set([...d.attachments, ...paths])],
+			}));
+		},
+		[draftKey, updateDraft],
+	);
 	const setQuotes = (updater: string[] | ((prev: string[]) => string[])) => {
 		updateDraft(draftKey, (d) => ({
 			...d,
@@ -160,6 +172,28 @@ export function Composer({ centered = false }: { centered?: boolean }) {
 		return () => window.removeEventListener(COMPOSER_FOCUS_EVENT, onFocusRequest);
 	}, []);
 
+	// Electron sandbox 中 File.path 已移除；preload 通过 webUtils 恢复原生路径并送入现有附件管线。
+	useEffect(() => {
+		if (readOnly) return;
+		const containsFiles = (event: DragEvent) => event.dataTransfer?.types.includes("Files") ?? false;
+		const onDragOver = (event: DragEvent) => {
+			if (!containsFiles(event)) return;
+			event.preventDefault();
+			if (event.dataTransfer) event.dataTransfer.dropEffect = "copy";
+		};
+		const onDrop = (event: DragEvent) => {
+			if (!containsFiles(event) || !event.dataTransfer) return;
+			event.preventDefault();
+			appendAttachments(resolveDroppedFilePaths(event.dataTransfer.files, getPi().getPathForFile));
+		};
+		window.addEventListener("dragover", onDragOver);
+		window.addEventListener("drop", onDrop);
+		return () => {
+			window.removeEventListener("dragover", onDragOver);
+			window.removeEventListener("drop", onDrop);
+		};
+	}, [appendAttachments, readOnly]);
+
 	// 点击输入框容器外部时收起命令/文件面板（文本保留；继续输入时恢复）
 	const { setSlashDismissed } = slash;
 	const { setAtDismissed } = at;
diff --git a/packages/desktop/src/renderer/src/components/composer/drop-files.test.ts b/packages/desktop/src/renderer/src/components/composer/drop-files.test.ts
new file mode 100644
index 0000000..a3ff739
--- /dev/null
+++ b/packages/desktop/src/renderer/src/components/composer/drop-files.test.ts
@@ -0,0 +1,29 @@
+import { describe, expect, it, vi } from "vitest";
+import { resolveDroppedFilePaths } from "./drop-files";
+
+describe("resolveDroppedFilePaths", () => {
+	it("resolves, de-duplicates, and skips files without a native path", () => {
+		const files = [{ path: "C:\\a.txt" }, { path: "" }, { path: "C:\\a.txt" }, { path: "C:\\b.md" }];
+		const getPathForFile = vi.fn((file: unknown) => (file as { path: string }).path);
+
+		expect(resolveDroppedFilePaths(files, getPathForFile)).toEqual(["C:\\a.txt", "C:\\b.md"]);
+		expect(getPathForFile).toHaveBeenCalledTimes(4);
+	});
+
+	it("preserves whitespace that is part of a native path", () => {
+		const path = "/tmp/report.pdf ";
+
+		expect(resolveDroppedFilePaths([{ path }], (file) => (file as { path: string }).path)).toEqual([path]);
+	});
+
+	it("ignores invalid drop entries instead of aborting the entire batch", () => {
+		const bad = {};
+		const good = {};
+		const getPathForFile = vi.fn((file: unknown) => {
+			if (file === bad) throw new TypeError("not a native File");
+			return file === good ? "/tmp/report.pdf" : "";
+		});
+
+		expect(resolveDroppedFilePaths([bad, good], getPathForFile)).toEqual(["/tmp/report.pdf"]);
+	});
+});
diff --git a/packages/desktop/src/renderer/src/components/composer/drop-files.ts b/packages/desktop/src/renderer/src/components/composer/drop-files.ts
new file mode 100644
index 0000000..73b4f58
--- /dev/null
+++ b/packages/desktop/src/renderer/src/components/composer/drop-files.ts
@@ -0,0 +1,19 @@
+/**
+ * Resolve native paths for files dropped into the sandboxed renderer.
+ * Electron can return an empty path for JS-created File objects, so those are ignored.
+ */
+export function resolveDroppedFilePaths(
+	files: ArrayLike<unknown>,
+	getPathForFile: (file: unknown) => string,
+): string[] {
+	const paths = new Set<string>();
+	for (const file of Array.from(files)) {
+		try {
+			const path = getPathForFile(file);
+			if (path.length > 0) paths.add(path);
+		} catch {
+			// Ignore values that are not native File objects instead of breaking the drop event.
+		}
+	}
+	return [...paths];
+}
diff --git a/packages/shared/src/ipc.ts b/packages/shared/src/ipc.ts
index 84350fb..5d7b8ca 100644
--- a/packages/shared/src/ipc.ts
+++ b/packages/shared/src/ipc.ts
@@ -31,11 +31,13 @@ export {
 /**
  * 渲染进程经 preload 暴露的 window.pi 类型。
  * invoke 成员：表化通道由 InvokeApi<CHANNEL_TABLE> 推导（shared/ipc-channels.ts 单一事实源，
- * key = 方法名）；表外成员（订阅 on*、platform）与迁移期遗留 invoke 在下方手写。
+ * key = 方法名）；表外成员（订阅 on*、platform、getPathForFile）在下方手写。
  */
 export interface PiApi extends InvokeApi<typeof CHANNEL_TABLE> {
 	/** 运行平台（preload 同步注入，供 renderer 按平台分流 UI：如顶栏红绿灯/窗口按钮留白） */
 	readonly platform: "darwin" | "win32" | "linux" | (string & {});
+	/** Electron 沙箱渲染器中的 File 不再带 path；由 preload 同步解析原生拖入文件路径。 */
+	getPathForFile(file: unknown): string;
 	/** 订阅登录流程事件（event/prompt/prompt-cancel，按 loginId 归属）；返回取消函数 */
 	onProviderLoginEvent(cb: (payload: LoginEventPayload) => void): () => void;
 	/** 订阅更新状态（checking/available/downloading/downloaded/error）；返回取消函数 */