Aiming at the problems of small working space and weak obstacle crossing ability for the current transmission line inspection robot, a transmission line inspection robot with the imitation of the inchworm movement is proposed by observing and analyzing the movement of the inchworm and combining with the principle of bionics. Kinematic method and virtual prototyping technology are used to simulate and analyze the peristaltic obstacle-crossing movement of the robot. The simulation results present that the robot structure is reasonable and with a large working space, it can cross complicated environment such as drainage lines by using peristaltic movement. The prototype was developed and placed in the simulated environment for experiments. The experimental results show that the center of gravity fluctuates smoothly and the performance of the robot is stable and reliable.