The working process of the well drilling rig can not be separated from the use of the pump, the use of the pump for trans-circulation operation. Under the action of atmospheric pressure, the circulating fluid flows from the sedimentation pool through the back ditch along the ring gap of the well hole to the bottom of the well, because at this time the turntable drives the drill pipe, drives the drill bit rotation to drill, the negative pressure established by the mud pump draws the debris mud into the drill pipe cavity, and then rises to the tap, through the mud pump draininto into the sediment pool, The precipitated circulatory fluid continues to flow into the wellbore, so that it is so repeated that a counter-cycle drilling work is formed. Mud or water enters from the drill pipe and flows out of the wellhead for a positive cycle drill. Mud or water is sucked out of the drill pipe and inflowed from the wellhead for a counter-cycle drill. Positive and negative cycle refers to the drilling fluid in the drilling machine in the circulation way said, drilling drill bit in the drilling will produce slag, slag, etc. , through the positive and negative cycle can be brought out by mud.