The invention discloses a dynamic property testing device for a large-drift-diameter ultrahigh-pressure electro-hydraulic proportional cartridge valve. The device mainly comprises a high-frequency hydraulic cylinder, a hydraulic cylinder output force control system and a specialized cartridge valve testing valve block, wherein the hydraulic cylinder output force control system and the specialized cartridge valve testing valve block are matched with the high-frequency hydraulic cylinder. According to the device, hydraulic power borne by a cartridge valve element in a switched-on state is mainly simulated by the hydraulic cylinder output force on the condition that fluid flowing is not adopted, the movement and controlled condition of the valve element are measured when the hydraulic cylinder acts, and then dynamic property parameter characteristic testing of the ultrahigh-pressure high-flow cartridge valve is achieved; dynamic property testing of the cartridge valve can be achieved in a laboratory on the condition that a high-flow pump unit is not needed, therefore, the testing cost is greatly reduced, the testing period is shortened, problems can be found and excluded in time when product approval testing is conducted, and the product research and development speed is increased.