Abstract: To meet the practical requirements of light weight and fewer driving motors, a novel unit module driven by a single motor and cables is proposed for the multi-link inspection robot for transmission lines, and the switching method of the supporting stands is presented by taking the advantage of the light weight characteristic of the cable driving. Afterwards, the concrete mechanism and the principle prototype of robot unit module are designed and the kinematic model of unit mechanism is established. The unit pitching motion experiment and the supporting stand switching experiment verify that the pitching angles of the unit are consistent with the simulation results, and the switching process of the supporting stands is stable. The experimental results show that the single motor cable driving method can reduce the number of robot driving motors, realize the switching of the supporting stands, and satisfy the requirements of robot crossing obstacles.