The invention discloses a liquid nitrogen pump equipment loading test and testing device and a test and testing method thereof, which are used for oil-gas field or coal bed gas nitrogen foam fracturing equipment tests. A waterpower damping device unit and a pressure regulation unit are specially arranged, wherein the waterpower damping device unit comprises a water tank, pump unit equipment and apipe manifold system connected in turn; the pipe manifold system mixes normal-temperature high-pressure gaseous nitrogen from liquid nitrogen pump equipment and high-pressure water from the pump unitequipment to form a high-pressure liquid and gaseous mixture; and the pressure regulation unit pressurizes water discharged from the waterpower damping device unit by adjusting the flow of the high-pressure liquid and gaseous mixture. By loading through a waterpower loading device, the invention avoids technical difficulty and security risk brought by pressure loading of gas; the pressure regulation system is easy, convenient and accurate to operate; the nitrogen discharge of the liquid nitrogen equipment is controlled by a power transmission system and a fluid distribution system of the equipment per se without additional power; and the equipment cost and energy are saved.