diff --git a/build.sh b/build.sh
index e954c5c..2c52976 100644
--- a/build.sh
+++ b/build.sh
@@ -29,6 +29,10 @@ else
   xgo -targets=linux/amd64,windows/amd64,darwin/amd64 -out enscan -ldflags="$ldflags"  .
 fi
 
+if [ -d 'build' ]; then
+    rm -rf build
+    echo "dir build existed, already removed."
+fi
 mkdir "build"
 mv enscan-* build
 cd build || exit
@@ -52,4 +56,4 @@ if [ "$1" == "release" ]; then
       zip compress/$(echo $i | sed 's/\.[^.]*$//').zip "$i"
     done
 fi
-cd ../..
\ No newline at end of file
+cd ../..