Abstract: A surmounting obstacle robot with 4 planetary wheels driven independently was developed according to the inner liner shape of industry rotary kiln.After some reasonable predigestions and hypothesizes, the surmounting obstacle process was divided into 5 phases, whose corresponding kinematic equations were built by means of MATLAB.The computational simulation was also performed for each surmounting phase.The effects of mechanical parameters of planetary wheels on the robot' s surmounting obstacle kinematics are also analyzed.