Abstract: The dynamics modeling was studied based on the lunar principle rover,and numerical simulations were analyzed.The mechanical properties of lunar soil were explained,and the stresses of driven and towed rigid wheels were analyzed according to terramechanics.The models were simplified to satisfy engineering requirement by using mathematical fitting.In terms of some hypotheses,the 3-DOF dynamics models were analyzed by using Newton-oula method.The interaction of driving and steering of the lunar rover was considered during modeling.The numerical simulation proves the dynamics model is validated.