3D2-S pump is small in size and compact in structure; power end adopts splash or forced lubrication with a stable and reliable transmission, reducing the friction coefficient and improving the lubricity; power end temperature rise is low, suitable for long time continuous operation; it can pump clear water, emulsion, and other chemical liquid similar with clear water. This pump is applied to coal excavation with high pressure water jetting, hydraulic liquid supply under the well, high pressure water jetting, metallurgy descaling, powder metallurgy, ship hull derusting, basic engineering, liquid transportation, engineering and pressure test for various rubber hose, metal tube and oilfield drilling equipment as well.