The project is designed for a large scale comprehensive astronomical application control system, which is part of the deep space exploration project in Academy of Sciences. The whole monitoring system, consisting of dozens of computers, is divided into four levels control. Two levels are stational, other two levels are the control center. The stational equipment computer system is developed by multiple institutes. The design technique of this large monitoring system is discussed. The strategies are utilized such as using background service technology to fulfill the network reading of each monitor application level, using INI files to realize saving configuration parameters, applying the memory alignment technique to accomplish the decoding of the protocol level, employing the multi screen display technology to fulfill the display of the interface. The monitoring program is designed as a whole, which means only needing to execute the unified system software in any level, any region. The programs select business requirements according to the configuration files respectively, which can reduce the workload of programming. The joint-test is quick and in a unified form.