diff --git a/action.yml b/action.yml
index a41fbbe9..c7ba47d9 100644
--- a/action.yml
+++ b/action.yml
@@ -300,6 +300,8 @@ runs:
     - id: assignees-after
       if: ${{ steps.reviewdog-enabled-pr.outputs.result == 'true' }}
       uses: actions/github-script@v6
+      env:
+        ASSIGNEES: ${{ inputs.assignees }}
       with:
           script: |
             var query = `query($owner:String!, $name:String!, $prnumber:Int!) { 
@@ -341,13 +343,17 @@ runs:
             ).flat())]
             
             console.log("assignees: %o", assignees);
-            return assignees.join('\n');
+            if (assignees.length > 0) {
+              return assignees.join(' ');
+            } else {
+              return process.env.ASSIGNEES.split(/\s+/).filter((str) => str !== '').join(' ');
+            }
 
     - id: assignee-removed-label
       if: ${{ steps.reviewdog-enabled-pr.outputs.result == 'true' }}
       uses: actions/github-script@v6
       env:
-        ASSIGNEES: ${{ steps.assignees-after.outputs.result && fromJson(steps.assignees-after.outputs.result) }}
+        ASSIGNEES: ${{ fromJson(steps.assignees-after.outputs.result) }}
       with:
         script: |
             const { ASSIGNEES } = process.env;
@@ -436,7 +442,7 @@ runs:
       if: ${{ steps.reviewdog-enabled-pr.outputs.result == 'true' && steps.should-trigger.outputs.result == 'true' }}
       with:
         github_token: ${{ inputs.github_token }}
-        assignees: ${{ fromJson(steps.assignees-after.outputs.result) }}
+        assignees: ${{ fromJson(steps.assignees-after.outputs.result.split(/\s+/).join("\n")) }}
     - if: ${{ steps.reviewdog-enabled-pr.outputs.result == 'true' && hashFiles('reviewdog.fail.log') }}
       shell: bash
       run: |
@@ -458,7 +464,7 @@ runs:
       with:
         slack_token: ${{ inputs.slack_token }}
         message: |
-          [semgrep] @${{ github.actor }} action failed, plz take a look. /cc ${{steps.assignees.outputs.result}} ${{ fromJson(steps.reviewdog-fail-log-head.outputs.result) }}
+          [semgrep] @${{ github.actor }} action failed, plz take a look. /cc ${{fromJson(steps.assignees-after.outputs.result).split(/\s+/).map(s=>"@"+s).join(" ")}} ${{ fromJson(steps.reviewdog-fail-log-head.outputs.result) }}
         channel: secops-hotspots
         color: red
         verbose: true
@@ -467,7 +473,7 @@ runs:
       with:
         slack_token: ${{ inputs.slack_token }}
         message: |
-          [semgrep] @${{ github.actor }} pushed commits. /cc ${{steps.assignees.outputs.result}}
+          [semgrep] @${{ github.actor }} pushed commits. /cc ${{fromJson(steps.assignees-after.outputs.result).split(/\s+/).map(s=>"@"+s).join(" ")}}
         channel: secops-hotspots
         color: green
         verbose: true