diff --git a/.gitea/workflows/preview-deploy.yml b/.gitea/workflows/preview-deploy.yml
index e5ad2f0c0..22cd780ab 100755
--- a/.gitea/workflows/preview-deploy.yml
+++ b/.gitea/workflows/preview-deploy.yml
@@ -184,6 +184,16 @@ jobs:
           exit 1
         fi
 
+        # SSH密钥完整性自检
+        if ! ssh-keygen -y -f "$key_path" > /dev/null 2>&1; then
+          echo "ERROR: SSH密钥损坏（private key contents do not match public）"
+          echo "请检查 PREVIEW_SSH_KEY secret 中的私钥是否完整正确"
+          echo "私钥文件大小: $(wc -c < "$key_path") 字节"
+          head -2 "$key_path"
+          exit 1
+        fi
+        echo "SSH key integrity check passed"
+
         ssh-keyscan -p "$preview_port" -H "$preview_host" >> ~/.ssh/known_hosts 2>/dev/null
         echo "SSH keyscan done"