diff --git a/install.sh b/install.sh
index c175ba2..de9760d 100755
--- a/install.sh
+++ b/install.sh
@@ -31,7 +31,8 @@ getCpuType () {
 # 检测是否已经安装了docker
 # 返回值：0 - 未安装，1 - 已安装
 detectDockerInstalled () {
-    if [ command -v docker > /dev/null ]; then
+    res=`command -v docker | wc -l`
+    if [ $res -gt 0 ]; then
         return 1
     fi