diff --git a/apps/web_v1/src/app/App.tsx b/apps/web_v1/src/app/App.tsx
index ee8bde4..681d48c 100644
--- a/apps/web_v1/src/app/App.tsx
+++ b/apps/web_v1/src/app/App.tsx
@@ -123,7 +123,7 @@ function App() {
   }, [session, workspaces])
 
   const dark = theme === 'dark'
-  const activeWorkspace = workspaces.find((workspace) => workspace.project.id === activeProjectID) ?? workspaces[0]
+  const activeWorkspace = workspaces.find((workspace) => workspace.project.id === activeProjectID)
   const activeTagOptions = activeWorkspace?.tags.filter((tag) => tag !== 'all' && tag !== '全部') ?? []
 
   function selectActiveProject(projectID: string) {
@@ -142,7 +142,7 @@ function App() {
     const requestedProjectID = latestProjectID !== projectIDWhenStarted
       ? latestProjectID
       : preferredProjectID ?? latestProjectID
-    const nextProjectID = backendWorkspaces.find((workspace) => workspace.project.id === requestedProjectID)?.project.id ?? backendWorkspaces[0]?.project.id ?? ''
+    const nextProjectID = backendWorkspaces.find((workspace) => workspace.project.id === requestedProjectID)?.project.id ?? ''
     selectActiveProject(nextProjectID)
     return backendWorkspaces
   }
@@ -152,9 +152,9 @@ function App() {
     try {
       setApiBaseUrl(input.server)
       const nextSession = await login(input.email, input.password)
-      const backendWorkspaces = await loadWorkspaces(nextSession, '')
+      await loadWorkspaces(nextSession, '')
       setSession(nextSession)
-      selectActiveProject(backendWorkspaces[0]?.project.id ?? '')
+      selectActiveProject('')
       setActiveChannel('overview')
       setActiveView('workspace')
       setScreen('workbench')
@@ -385,7 +385,7 @@ function App() {
           <Spin loading={loading} style={{ width: '100%' }}>
             <LoginPage onLogin={handleLogin} />
           </Spin>
-        ) : activeWorkspace && session ? (
+        ) : session ? (
           <ProjectPage
             activeView={activeView}
             activeWorkspace={activeWorkspace}
diff --git a/apps/web_v1/src/pages/projects/project-rail.tsx b/apps/web_v1/src/pages/projects/project-rail.tsx
index 3cf8dce..181a0fc 100644
--- a/apps/web_v1/src/pages/projects/project-rail.tsx
+++ b/apps/web_v1/src/pages/projects/project-rail.tsx
@@ -14,7 +14,7 @@ export function ProjectRail({
   onSelectProject,
   onCreateProject,
 }: {
-  activeProject: Project
+  activeProject?: Project
   projects: Project[]
   activeView: WorkbenchView
   onSelectWorkspace: () => void
@@ -42,7 +42,7 @@ export function ProjectRail({
         {projects.map((project) => (
           <Badge key={project.id} count={project.badge} dot={false} className={project.urgent ? 'project-badge urgent' : 'project-badge'}>
             <button
-              className={activeView === 'project' && activeProject.id === project.id ? 'project-button active' : 'project-button'}
+              className={activeView === 'project' && activeProject?.id === project.id ? 'project-button active' : 'project-button'}
               onClick={() => onSelectProject(project)}
               style={{ '--project-color': project.color } as CSSProperties}
               title={project.name}
diff --git a/apps/web_v1/src/pages/workspace-explore.tsx b/apps/web_v1/src/pages/workspace-explore.tsx
index de54c70..15e56cf 100644
--- a/apps/web_v1/src/pages/workspace-explore.tsx
+++ b/apps/web_v1/src/pages/workspace-explore.tsx
@@ -452,9 +452,11 @@ export function WorkspaceExplorePage({
                     onClick={() => void updateSelected({ status: selected.status, starred: !selected.starred })}
                   />
                   <Button
-                    aria-label={`沉淀到项目${activeProjectName}`}
+                    aria-label={activeProjectName ? `沉淀到项目${activeProjectName}` : '请先选择项目'}
+                    title={activeProjectName ? undefined : '请先选择项目'}
                     type="text"
                     icon={<IconBook />}
+                    disabled={!activeProjectID}
                     loading={depositingItemID === selected.id}
                     onClick={() => void depositSelected()}
                   />
diff --git a/apps/web_v1/src/pages/workspace-home.tsx b/apps/web_v1/src/pages/workspace-home.tsx
index 1b512d4..3939017 100644
--- a/apps/web_v1/src/pages/workspace-home.tsx
+++ b/apps/web_v1/src/pages/workspace-home.tsx
@@ -67,7 +67,7 @@ export function ProjectPage({
   onDepositDatasetItem,
 }: {
   activeView: WorkbenchView
-  activeWorkspace: ProjectWorkspace
+  activeWorkspace?: ProjectWorkspace
   workspaces: ProjectWorkspace[]
   activeChannel: ChannelKey
   activeTaskID: string | null
@@ -108,9 +108,10 @@ export function ProjectPage({
   onSyncDatasetSources: () => Promise<DatasetSyncResultDTO[]>
   onDepositDatasetItem: (itemId: string, projectId: string) => Promise<DatasetDepositDTO & { refreshFailed?: boolean }>
 }) {
-  const isProject = activeView === 'project'
+  const isProject = activeView === 'project' && Boolean(activeWorkspace)
   const projects = workspaces.map((workspace) => workspace.project)
   const updateActiveProjectTask = (update: ProjectTaskUpdate) => {
+    if (!activeWorkspace) return
     onUpdateWorkspaceTask({
       originalProjectId: activeWorkspace.project.id,
       nextProjectId: activeWorkspace.project.id,
@@ -138,7 +139,7 @@ export function ProjectPage({
 
       <Layout className="workbench-main" hasSider>
         <ProjectRail
-          activeProject={activeWorkspace.project}
+          activeProject={activeWorkspace?.project}
           projects={projects}
           activeView={activeView}
           onSelectWorkspace={onSelectWorkspace}
@@ -147,7 +148,7 @@ export function ProjectPage({
           onCreateProject={onCreateProject}
         />
 
-        {isProject && (
+        {isProject && activeWorkspace && (
           <ProjectSidebar
             activeView={activeView}
             activeWorkspace={activeWorkspace}
@@ -163,8 +164,8 @@ export function ProjectPage({
             <WorkspacePage workspaces={workspaces} onOpenTask={onOpenTask} onUpdateTask={onUpdateWorkspaceTask} />
           ) : activeView === 'workspace-explore' ? (
             <WorkspaceExplorePage
-              activeProjectID={activeWorkspace.project.id}
-              activeProjectName={activeWorkspace.project.name}
+              activeProjectID={activeWorkspace?.project.id ?? ''}
+              activeProjectName={activeWorkspace?.project.name ?? ''}
               onListSources={onListDatasetSources}
               onListItems={onListDatasetItems}
               onCreateSource={onCreateDatasetSource}
@@ -174,7 +175,7 @@ export function ProjectPage({
               onSyncSources={onSyncDatasetSources}
               onDepositItem={onDepositDatasetItem}
             />
-          ) : (
+          ) : activeWorkspace ? (
             <ProjectChannelPage
               activeChannel={activeChannel}
               activeWorkspace={activeWorkspace}
@@ -193,6 +194,8 @@ export function ProjectPage({
               onListAIExperts={onListAIExperts}
               onCreateAISession={onCreateAISession}
             />
+          ) : (
+            <WorkspacePage workspaces={workspaces} onOpenTask={onOpenTask} onUpdateTask={onUpdateWorkspaceTask} />
           )}
         </Content>