With the rapid development of complex adaptive systems, traditional modeling and simulation methods have been unable to meet the need of accurate modeling of complex adaptive systems. Therefore, we need a way to accurately describe the characteristics of complex adaptive systems modeling and simulation. Multi-Agent modeling and simulation methods focus on the study of the interaction between multiple subjects. It is an effective way to study complex adaptive system. This paper analyzes the multi-agent modeling process, sets up a rumor spreading model of a small social network through multi-agent modeling and simulation methods,. The simulation results verify the correctness and accuracy of the model.