Aiming at the problems of insufficient safety and weak running stability of self-propelled Panax notoginseng combine harvester in field operation, the driving performance of the chassis under the condition of clay soil was studied. Firstly, theoretical analysis was carried out under the driving conditions of the harvester such as straight and steering, longitudinal and transverse climbing and crossing the obstacles, etc., and various factors influencing the driving performance were obtained. Secondly, multi-body dynamics simulation analysis was carried out by ADAMS ATV, and Euler angle and corresponding angular velocity curve were drawn under the driving conditions. A 1∶4 miniature platform model of the combine harvester chassis was designed by using the dimensional analysis method of similarity theory, and the driving performance of scaling model experiment was carried out under the three typical driving conditions of longitudinal climbing, crossing the ditch, and climbing over the ridge. The simulation results showed that the combine harvester chassis had smooth straight running and steering performance, which can pass through 30° longitudinal slope, 20° transverse slope, 600mm ditch and 300mm ridge smoothly. The model experiment results showed that the model can pass through 30° longitudinal slope, 150mm ditch and 75mm ridge smoothly. The trend of the pitch angle and corresponding angular velocity curve were consistent with the simulation under the above three conditions, and the amplitude change of the pitch angle curve obtained under the two conditions was equivalent. The experimentation error was mainly affected by the actual terrain flatness and soil evenness. It showed that the scaling model experiment can verify the correctness of the simulation results. Through the prediction of the model to the prototype and the simulation results, the design requirements of the trafficability for the harvester were satisfied. The research result can provide a theoretical foundation and reference for design of the root combine harvester chassis in the hilly and mountainous areas.