Abstract: The advantages and disadvantages of existing crawler travelling mechanisms of coal mine rescue robot were analyzed from structure complexity, obstacle surmounting performance, operability and ground bearing distribution. In view of advantages and disadvantages of existing crawler travelling mechanisms, a new structure of crawler mechanism was designed, and the optimization calculation formulas of the main structure dimensions was given combined with relevant requirements of rescue robots. CUMT-5 type robot was designed according to the proposed calculation formulas. The practical application results of CUMT-5 type robot show that the new type of crawler travelling mechanism has simple structure, good performance in obstacle surmounting and good maneuverability.