Pump for water injection, composed of main components such as high-pressure pump, explosion-proof motor, stainless steel automatic unloading hydraulic control valve, and base. The high-pressure pump (using German technology) is made up of an immersed lubricated crankshaft rotation, damage-free ceramic plunger, forged brass pump body, and automatic unloading hydraulic control valve; it can operate continuously for 24 hours without interruption. The automatic unloading hydraulic control valve is used in fixed displacement automatic pressure control systems, which can automatically unload the pump and release pressure when the pressure pipeline is completely closed, saving energy and extending the pump's service life. It features lightweight, energy-saving, easy mobility, and long lifespan; suitable for pumping clean water, emulsion, and applicable to spray dust removal, coal seam water injection, and underground hydraulic support fluid supply.