diff --git a/__pycache__/backend.cpython-39.pyc b/__pycache__/backend.cpython-39.pyc
index 1fad2ed..2345c4b 100644
Binary files a/__pycache__/backend.cpython-39.pyc and b/__pycache__/backend.cpython-39.pyc differ
diff --git a/backend.py b/backend.py
index 3485fec..5ab4f82 100644
--- a/backend.py
+++ b/backend.py
@@ -1194,6 +1194,16 @@ def check_and_install_efi_modules(mount_point: str, distro_type: str, is_uefi: b
         log_warning(f"未知的发行版 '{distro_type}'，无法自动安装 EFI 模块")
         return False, f"无法确定 {distro_type} 的 EFI 包名"
     
+    # 安装 EFI 包前，先确保网络连接（复制 DNS 配置）
+    resolv_source = "/etc/resolv.conf"
+    resolv_target = os.path.join(mount_point, "etc/resolv.conf")
+    if os.path.exists(resolv_source):
+        try:
+            shutil.copy2(resolv_source, resolv_target)
+            log_info("已复制 DNS 配置到 chroot 环境")
+        except Exception as e:
+            log_debug(f"复制 DNS 配置失败: {e}")
+    
     # 安装 EFI 包
     if distro_type in ["centos", "rhel", "fedora", "rocky", "almalinux"]:
         success, _, stderr = run_command(
@@ -1202,6 +1212,11 @@ def check_and_install_efi_modules(mount_point: str, distro_type: str, is_uefi: b
             timeout=300
         )
     elif distro_type in ["debian", "ubuntu"]:
+        success, _, stderr = run_command(
+            chroot_cmd_prefix + ["apt-get", "update"],
+            f"更新包列表",
+            timeout=120
+        )
         success, _, stderr = run_command(
             chroot_cmd_prefix + ["apt-get", "install", "-y"] + efi_packages,
             f"安装 UEFI GRUB 包",
@@ -1209,7 +1224,7 @@ def check_and_install_efi_modules(mount_point: str, distro_type: str, is_uefi: b
         )
     elif distro_type in ["arch", "manjaro"]:
         success, _, stderr = run_command(
-            chroot_cmd_prefix + ["pacman", "-S", "--noconfirm"] + efi_packages,
+            chroot_cmd_prefix + ["pacman", "-Sy", "--noconfirm"] + efi_packages,
             f"安装 UEFI GRUB 包",
             timeout=300
         )