The invention provides a power adjusting system of a plunger type duplex tilting tray variable pump. The system comprises a pressure sensing transmitter set, the plunger type duplex tilting tray variable pump, a power adjusting module, a computer host controller and an engine. A measurement numerical value of the pressure sensing transmitter set is transmitted to the computer host controller; the computer host controller adjusts the plunger type duplex tilting tray variable pump through the power adjusting module; the computer host controller comprises a three-dimensional dot-matrix type MCU constant power controller composed of a single chip microcomputer; curvilinear coordinate parameters with lattice parameters composed of three-dimensional arrays are searched according to numerical numbers, collected by the pressure sensing transmitter set, of pressure output by the plunger type duplex tilting tray variable pump, then the power adjusting module is controlled to adjust flow output by the plunger type duplex tilting tray variable pump, so that power, absorbed by the plunger type duplex tilting tray variable pump, of the engine keeps constant, the plunger type duplex tilting tray variable pump is adjusted in a mode approaching to a real constant power curve in the practical work process, the capacity of the engine can be played fully, the flow of the plunger type duplex tilting tray variable pump when a system overflows can be lowered greatly, power loss is reduced and fuel oil is saved.