Abstract: In view of the shortage of hydraulic transmission and function realization of underground drilling rig in coal mine,combined with the demand of “mechanized replacement,automatic reduction” in drilling construction in the future,the design idea of automatic underground tunnel drill with integral crawler layout is put forward.The overall structure and scheme of drilling rig are worked out,and the key actuators,such as active drill pipe type chuck slewing device,clamping and unloading device,automatic angle adjusting and controllable drilling feed device,automatic rod adding device and othars,are developed.A parameter monitoring system and a multi-function electro-hydraulic control system are developed.The technical performance of the drill is verified by drilling test on the ground ,in which about 55 s for a single drill pipe to complete the drilling and about 50 s for automatic unloading.The test results show that the performance of automatic drill is reliable and the function is perfect,high degree of automation,low labor intensity of workers.