In order to acquire the S- shaped carbon- free car steering mechanism with symmetrical motion law and easy to adjust,the cam- slider- crank mechanism model is proposed. the model’s motion is symmetrical. The kinematics simulation is carried out by using ADAMS software,the rocker- slider mechanism is studied and designed by using the method of parametric modeling,then cam profile is got by the method of reverse design,finally the cam- rocker- slider simulation model is set up,the simulation results show that the motion law is symmetrical,this model is conforms to the requirements of the steering mechanism. At the same time,a set of test device is designed to verify the simulation results,the test data shows that the correctness of the simulation model and the feasibility of the method,the reference for the design of the S- shaped carbon-free car cam steering mechanism and related applications are provided by the simulation model,the ideas for simulation model validation and accuracy detection are provided by test method.