The invention discloses a power head slip clamping device. two ends of an oil cylinder are respectively connected with a box body and a bearing pedestal, a main shaft is arranged in the box body, anda slip is arranged in a slip groove of the main shaft; a rotating sleeve is arranged in the bearing pedestal, a slip bowl is fixedly arranged at one end of the rotating sleeve, and the slip bowl is matched with the slip through a conical surface; the oil cylinder drives the slip to slide in the slip bowl and ascend and descend in the slip groove at the same time. The whole structure is simpler, and the oil cylinder arranged outside the power head has a larger movement stroke. a piston rod of the oil cylinder does telescopic motion, the bearing pedestal, the rotating sleeve and the slip bowl are integrally driven to move left and right, the left-right movement of the slip bowl is converted into the up-down movement of the slip bowl through conical surface matching, so that a drilling tool is clamped and loosened, and due to the fact that the telescopic movement stroke of the oil cylinder is increased, the up-down movement stroke of the slip is also increased, and the oil cylinder can guarantee larger and more stable clamping force.