The utility model relates to a dissembler for a piston clamp spring of a slush pump, which belongs to the technical field of oil drilling equipment, and relates to a device for assembling and dissembling a piston clamp spring of an oil-drilling slush pump. The dissembler comprises a hydraulic cylinder, a clamp spring pressing mold, a clamp spring guiding mold and a clamp spring dissembling mold. The utility model has the benefits that the piston clamp spring of the slush pump can be conveniently assembled and dissembled at a well site by utilizing the hydraulic principle, the operation is simple, the time and the labor are saved, and the safe production is ensured as well.