Abstract: The calculation method of kinematic envelope by dynamic model simulation has been widely applied in China. Dynamic model is the key factor influencing vehicle body kinematic envelope calculation precision, which can be verified through vehicle body sway test. Taking the trailer and motor vehicles of certain metro train as the research object, by establishing vehicle non\|linear dynamic simulation model, vehicle body sway test is carried out. Through analysis of relative error between simulation and test, the accuracy of simulation model is verified. Orthogonal tests of key suspension parameters are designed, and the influence of these parameters on vehicle body side\|swing angle sensitivity is analyzed, as well as the impact of key suspension component non\|linearity on error.