diff --git a/pipeline_service/init.py b/pipeline_service/init.py
index 147affc..79667b4 100644
--- a/pipeline_service/init.py
+++ b/pipeline_service/init.py
@@ -375,15 +375,25 @@ def pipeline_unregister_step_type(step_type):
 # ── Git / Shell 操作（v3.2.1: 主agent devops 能力）──
 
 _SHELL_BASE_DIR = '/d/pipeline/workspaces'
+_WORKDIR_FALLBACK = '/tmp/pipeline_workspaces'
+
+def _resolve_workdir():
+    """选择可写的工作目录根。"""
+    if os.path.isdir(_SHELL_BASE_DIR) or os.access(os.path.dirname(_SHELL_BASE_DIR), os.W_OK):
+        return _SHELL_BASE_DIR
+    os.makedirs(_WORKDIR_FALLBACK, exist_ok=True)
+    return _WORKDIR_FALLBACK
 
 async def shell_exec(command: str, workdir: str = None, timeout: int = 60):
     """安全外壳执行。限制在 workspace 目录下，超时自动终止。
     
     Returns: {"rc": exit_code, "stdout": "...", "stderr": "..."}
     """
-    cwd = workdir or _SHELL_BASE_DIR
+    cwd = workdir or _resolve_workdir()
     cwd = os.path.abspath(cwd)
-    if not cwd.startswith(os.path.abspath(_SHELL_BASE_DIR)):
+    base = os.path.abspath(_SHELL_BASE_DIR)
+    fallback = os.path.abspath(_WORKDIR_FALLBACK)
+    if not (cwd.startswith(base) or cwd.startswith(fallback)):
         return {"rc": -1, "stdout": "", "stderr": f"安全限制：工作目录必须在 {_SHELL_BASE_DIR} 下"}
     try:
         proc = await asyncio.create_subprocess_shell(
@@ -409,10 +419,10 @@ async def skill_import_git(repo_url: str, skills_dir: str = 'skills'):
     """
     from appPublic.uniqueID import getID
     repo_name = repo_url.rstrip('/').split('/')[-1].replace('.git', '') or f"repo_{getID()[:8]}"
-    target = os.path.join(_SHELL_BASE_DIR, repo_name)
+    target = os.path.join(_resolve_workdir(), repo_name)
     
     if not os.path.isdir(target):
-        r = await shell_exec(f'git clone {repo_url} {target}', workdir=_SHELL_BASE_DIR)
+        r = await shell_exec(f'git clone {repo_url} {target}', workdir=_resolve_workdir())
         if r['rc'] != 0:
             return {"success": False, "error": f"clone 失败: {r['stderr'][:500]}"}