The invention discloses an overhead transmission line cleaning robot. The overhead transmission line cleaning robot is composed of a plurality of module structures. Each module structure comprises a movable trolley, a power source module, a cleaning motor, a servo driver, a compressing device and a cleaning device, wherein the movable trolley is hung on an overhead transmission line and can move back and forth along the overhead transmission line; the power source module, the cleaning motor, the servo driver and the compressing device are installed on an upper cover board of the movable trolley; the lower portion of the upper cover board is connected with the cleaning device. The overhead transmission line cleaning robot can be independently used and can also be used in cooperation with a spraying robot. The modular structure and design are adopted, so that the design cost is effectively lowered, the universality is improved, and the overhead transmission line in the exposed mode is cleaned in an efficient, safe and high-quality mode.