Abstract: In order to meet the design requirements of the end-actuator of the drill pipe loading and unloading robot in coal mines, a hydraulic permanent magnet drill pipe grabbing device was developed. The structural characteristics and the process flow of the drill pipe loading and unloading robot are analyzed, and the method of mechanical clamping and positioning after magnetic suction is proposed to solve the grasping problem of the drill pipe which were tightly stacked in the drill pipe bin and the end compliance problem of the robot; the transmission clearance of the device is eliminated and the precise positioning of the drill pipe is realized. The rationality of the selection of key technical parameters of the device is verified by theoretical calculation. The test results show that the gripping force of the grasping device meets the design and use requirements; the robot in different technological processes can work within the rated load range. However, the use of magnetic force to realize the pick and place of the drill pipe requires special attention to ensure that the surface of the drill pipe is clean.