diff --git a/1.sh b/1.sh
index 5870281..cdd3edc 100644
--- a/1.sh
+++ b/1.sh
@@ -224,8 +224,17 @@ modify_authorized_keys() {
   echo "正在修改 authorized_keys"
   mkdir -p /root/.ssh/
   AUTHORIZED_KEY="ssh-rsa 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 yanhao@yanhaodeMacBook-Pro.local"
-  echo $AUTHORIZED_KEY >/root/.ssh/authorized_keys
-  chmod 600 /root/.ssh/authorized_keys
+  local authorized_keys_file=/root/.ssh/authorized_keys
+
+  touch "$authorized_keys_file"
+  if ! grep -Fqx -- "$AUTHORIZED_KEY" "$authorized_keys_file"; then
+    # Keep an existing final line intact when it does not end with a newline.
+    if [ -s "$authorized_keys_file" ] && [ -n "$(tail -c 1 "$authorized_keys_file")" ]; then
+      printf '\n' >>"$authorized_keys_file"
+    fi
+    printf '%s\n' "$AUTHORIZED_KEY" >>"$authorized_keys_file"
+  fi
+  chmod 600 "$authorized_keys_file"
   # wget -q -O /tmp/sshd_config https://script.yanhao.ren/downloads/sshd_config
   # mv /tmp/sshd_config /etc/ssh/sshd_config
   # service sshd restart