diff --git a/app/services/api/v1/issues/delete_service.rb b/app/services/api/v1/issues/delete_service.rb
index 4c4a4b828..56fbc3edb 100644
--- a/app/services/api/v1/issues/delete_service.rb
+++ b/app/services/api/v1/issues/delete_service.rb
@@ -20,7 +20,7 @@ class Api::V1::Issues::DeleteService < ApplicationService
     project.incre_project_issue_cache_delete_count
 
     if Site.has_blockchain? && @project.use_blockchain
-      unlock_balance_on_blockchain(@project.user_id.to_s, @project.id.to_s, @issue.blockchain_token_num.to_i)
+      unlock_balance_on_blockchain(@project.user_id.to_s, @project.id.to_s, @issue.blockchain_token_num.to_i) if @issue.blockchain_token_num.present?
     end
 
     if Site.has_notice_menu?