An efficiency analysis method in multi-system and multi-platform operation is presented in the paper based on their simulation. It is achieved by using intelligent reasoning and optimal technology in the efficiency simulation of multi-system and multi-platform operation to coordinate scientifically sub-systems and achieve combination of subjective and objective. The method is used to simulate the combat effectiveness in the combined operations, based on the efficiency analysis of single weapon and single platform, and to obtain requirements relevant to the single weapon and the single platform in a view of an overall efficiency. The method will help to obtain the optimal combination of multi-platform and multi-system in combined operations and will be a future reference for equipment development.