A micro piping robot is able to help people finish tasks such as inspection inside a mini pipe. Research on the mobile mechanism of the robot is very important in the robot researching area. The kinematics and dynamics characteristics of the mobile mechanism for a planetary gears driven micro robot have been studied. The operation, the principle and the affect factors of the mobile mechanism have been discussed in detail. In order to drive the robot well, the adhesion and the power of the mobile mechanism should be increased as the influence of its autoeciousness power has been reduced.