Building an online service platform complies with the requirement of “The Education Informatization 2.0 Action Plan” for the smart campus construction in colleges and universities. In this study, combined with the actual cases of online service platforms, the integrated modeling, elements, and steps that meet the needs of multi-campus management are proposed from the view of integrated management of multi-campus services. The component system based on the workflow-as-a-service is developed and a unified service user interface is presented. At last, the effectiveness of the modeling method and design is illustrated through the practical example which is applied in a practical scenario.