The bionic quadruped robot is widely studied in recent years.Because of its particularity walking mechanism,the main application of environmental conditions could be mountain and plateau and other nonstructured terrain.Therefore,the walking environment of quadruped robot is mainly on the soft soil which could cause some degree of slippage.A quadruped robot prototypes outdoor test results show that the slip rate is obvious influence on the robot dynamics and control algorithm.It is necessary to study the mechanical relationship between the bionic foot and the terrain with soft soil.However,the researches on this field have not too much.