Combat simulation is an important part of simulation war. There is a big error between the analysis, processing and calculation of the battlefield situation of the combat simulation system developed by various scientific theoretical methods of the traditional linear machinery and the actual situation. Firstly, the method of combat modeling and simulation based on Multi-Agent and the process of combat model modeling based on multi-agent are studied, and the combat scenario is formulated. Secondly, the types of agents are extended, and the roles and relations of each agent are emphasized. Finally, based on the anylogic development platform, a new complex multi-agent combat simulation model is proposed, which expands the types of agents in the combat simulation model. The simulation results show that the agents in the new complex multi-agent combat simulation model are more comprehensive and more close to the real combat scene of modern war.