In order to analyze the dynamic characteristics of the vehicle exhaust system, it is studied by calculating modal analysis and experiment modal analysis technique, respectively. The first six order modal parameters of the exhaust system are obtained. By comparison, it is found that the error of the first sixorder natural frequency calculation and the experimental result is less than 6.5%, modal shapes are basically consistent. Then the dynamic characteristic of the exhaust system is evaluated according to the result of calculation and experiment. It is found that the vehicle exhaust system will not occur resonance under the excitation of resonance in idle speed and economic speed, and the weak link of the system is analyzed. The research methods and results have guiding significance for the dynamic characteristic design of vehicle exhaust system.