The traditional manual maintenance and safety inspection of high poles and cables bear high safety risks. To address these issues, the article proposed a design of an inchwormoid pole-climbing robot and its gait control scheme. By studying the structural characteristics and working posture of the existing rod-climbing robot, analyzing the changing patterns of the inchworm’s crawling postures, a modular inchwormoid pole-climbing robot with 4 degrees of freedom was designed. The three-dimensional structure model of the robot was established by SOLIDWORKS software. The gait mathematical model of the robot was established through the inverse kinematics solution. The multi-objective particle swarm optimization theory was employed to achieve the optimization of low energy consumption and stable climbing. The effectiveness of the optimization control method was verified by experiments.