According to the requirements of the power department, a new type of inspection robot that works along ground wires is developed in this paper. The robot can navigate counterweights, clamps and particular the towers autonomously. The locomotion principle of tower-navigation is presented. In order to decrease the mass eccentricity of the robot, a centroid balance method is proposed. Virtual prototyping technical is used to validate the centroid balance method. It proved that the proper movement of the electric box can adjust the robot centroid distribution efficiently. Driven torque and the power cost of the whole system both decrease a lot. And the robot works more safely.