The invention discloses an extra-high voltage transmission line inspection auxiliary maintenance robot and method. The extra-high voltage transmission line inspection auxiliary maintenance robot comprises two walking devices capable of moving on an anti-falling rail. The two walking devices are a first walking device and a second walking device respectively. The first walking device and the secondwalking device are connected through a connecting support. 360-degree horizontal rotating mechanisms are arranged at the joint of the first walking device and the connecting support and the joint ofthe second walking device and the connecting support. A 45-degree vertical tilting mechanism is further arranged at the joint of the first walking device and the connecting support. A video head is installed on the first walking device, a thermal imaging camera and a visible light camera are installed on the second walking device, a control box used for controlling the walking device, the 360-degree horizontal rotating mechanisms and the 45-degree vertical tilting mechanism is arranged on an installation plate, and the control box is remotely controlled by a ground device. According to the invention, the detection efficiency can be improved, the safety of workers is improved, and the labor intensity of front-line workers is greatly reduced.