The key on expanding the application range of quadruped robot is how to improve the locomotion speed.The impact force on the feet caused by the high speed should not be ignored.The buffering mechanism applied to the robot joint is one of ways to reduce the ground impact at the high speed locomotion and to decrease the driving torque (force) and the peak value of the driving power.The present research on the leg of robot with the buffering joint is focused on the analyses of the single leg mechanism or simplifying the model of quadruped robot as a spring-mass model.Some assumption mentioned in these researches make the practical result of locomotion act in disaccord with the real robot.The main reason is that the robot with the buffering joint is a multivariable,strong coupling and nonlinear control system.There has no good method to deal with this problem.In this article,a quadruped robot mechanism system with multi-buffering joints and gait planning based on CPG (central pattern generator) is designed by the multi-field collaborative modeling and simulation method.At the same time,according to the conclusion offered by virtual prototyping,the dynamic and kinematics analyses about the virtual prototyping are researched.At the same time,according to the result of the dynamic and kinematics analyses offered by virtual prototyping,we can draw some conclusions on quadruped robot design and gait planning.