The utility model discloses a supporting-leg-type pneumatic propelling drilling machine which comprises a rear supporting base, a propelling cylinder, a connecting element, a pneumatic drilling machine body, a drill rod, a sliding channel, a sliding base and a front supporting leg. The sliding channel is fixed to the upper portion of the rear supporting base and the upper portion of the front supporting leg, the propelling cylinder is fixed to the upper portion of the rear end of the sliding channel, a piston end of the propelling cylinder is connected with the tail portion of the pneumatic drilling machine body through the connecting element, the lower portion of the pneumatic drilling machine body is provided with the sliding base arranged on the sliding channel, and the front end of the pneumatic drilling machine body is provided with the drill rod. The supporting-leg-type pneumatic propelling drilling machine has the advantages of being low in work intensity, high in construction efficiency, safe in operation and the like.