A service-oriented modular system architecture. The service-oriented modular system architecture has plugins and an application programming interface (API) Nexus. The plugins abstract different functions in servers into pluggable business modules. Any numbers of API dispatchers can be registered on the API Nexus so that one business module in the plugins dynamically exposes the services, which can be provided at present, to other business modules in the plugins in a manner of API. Different functions in the server application are independently abstracted into different pluggable business modules, the separating effect of respectively encapsulating and separating different functions to obtain subservices is achieved, and different business modules are allowed to expose interfaces with each other for use.