Abstract: The basic design principles and structural characteristics of the feeding device of drilling rig in underground coal mine are analyzed. According to the demand of long-stroke, a feeding device by the series and parallel combination cylinder is developed, the theoretical calculation method of key parameters of the feeding device is given, and the changes of effective feeding force and pulling force are analyzed by fitting curve. The analysis shows that the effective feeding force and pulling force decrease with the increase of wear. The maximum feeding force and pulling force of the drilling rig were tested, and the validity of the theoretical calculation method was verified.