In order to solve the problem that the launching system of the rocket launcher in the marching process is difficult to define the boundary in the dynamic analysis, a research method combining experimental and numerical simulation is proposed. According to the principle of similarity and modeling, the design of an experiment to simulate the rocket driving vibration system, and simulate random road principle to generate road spectrum based on the sine superposition. Establish the experimental car bench test system of rigid flexible coupling in Adams, simulate experiment vehicle bench and compare it and analyze it with data. The results show that the method has high precision, it can meet the error requirement of engineering research, and it can be used in rocket system dynamic analysis research.