The invention discloses a robot airship control system for overhead line inspection and a control method thereof. The control system comprises a on-board system and a ground-based system, wherein the on-board system has a structure that: a master controller DSP is connected with various sensors, a wireless communication module, a motor drive circuit, an image processor DSP and the like through analog-to-digital conversion ports, serial ports and other ports, and the image processor DSP is connected with an infrared CCD through an HPI port; the ground-based system has a structure that: an interface singlechip is connected with a ground PC, wireless communication equipment and a manual remote controller through serial ports, I/O and other ports; the on-board system and the ground-based system are communicated through an on-board wireless communication module and a ground-based wireless communication module; and a wireless camera transmits image information to the ground-based system through wireless video signals, and displays the image information on an image monitor. The robot airship control system for the overhead line inspection has three patterns, namely an infrared vision navigation pattern, a GPS navigation pattern and a manual remote control pattern, and has the advantages of high inspection efficiency, high cruisingability and high safety.