Web service could make events and data generated in software products as service by which software products interact with each other. Workflow is a very popular way to deal with message flow and event flow which could deliver events and data among software products. It is very meaningful to study Gitlab which is known as a widely used open source code and document management tool. However, poor flexibility, weak expandability and raw service granularity are found in Gitlab service during the study. To tackle the problems in Gitlab, this paper proposes a new service solution to Gitlab which redefines the service process, service standard and service implement. To implement the services, we design and implement new solutions for listening services and execution services which involve the message queue and asynchronous mechanism. According to experimental analysis to this solution, GITService has high flexibility, strong expandability and intensive service granularity with little cost of time. The solution we provide in this paper is of significance to design and implementation of service in other situations.