For solving the safety hazards and inspection safety problems in the long-term operation of cable tunnel transmission, on the investigation of the working environment and requirements, an arm-type cable tunnel inspection robot was designed. Making the kinematics analysis for this robot, a robot-to-barrier method is proposed and the obstacle path is planned. And then the kinematics and dynamics analysis of the climbing process were carried out, and calculate the theoretical value of the biggest obstacle that the robot can cross. By establishing a robot simulation model to simulate the climbing steps and climbing process of the robot. Finally, a variety of environmental experiments were conducted for the inspection robots, and demonstration applications were carried out in actual cable tunnels. The test and demonstration application results show that the robot has smooth and flexible movement, strong environmental adaptability, the ability for reliable communication and convenient operation so that it can meet the requirements of inspection operations.