The invention discloses an automatic power transmission line inspection robot ground wire climbing-on/off system having the fall prevention function. The system comprises a line tower and further comprises a walking guide rail, a robot bearing device, a power traction device and a wire climbing-on/off leading device, wherein the walking guide rail is fixed on the line tower, the robot bearing device is arranged on the walking guide rail, the wire climbing-on/off leading device is arranged at a top end of the walking guide rail, the power traction device is arranged at a top portion of the line tower, an output end of the power traction device is connected with the robot bearing device, and a top end of the line tower is fixedly provided with a ground wire support. The system is advantaged in that the automatic ground wire climbing-on/off problem and the anti-fall protection problem in the automatic ground wire climbing-on/off process of a power transmission line inspection robot are solved, the structure is simple and light, the system is convenient to mount, influence on towers and high-voltage power transmission lines can be avoided, and the system is suitable for various types of towers and ground wire structures.