A large-flow safety valve test system comprises a large-flow control valve block, an accumulator hydraulic power source, a pressurizing cylinder attached with a stroke sensor, an electric control test system and the like. The large-flow control valve block is connected with the accumulator hydraulic power source and the pressurizing cylinder and controlled by the electric control test system, a pressurizing cavity of the pressurizing cylinder is connected with a safety valve to be tested, an interface of the safety valve to be tested is connected with a pressure sensor, and the pressure sensor and the stroke sensor are connected with the electric control test system. The large-flow control valve block consists of an electromagnetic pilot valve and a pilot operated directional control valve block, the pilot operated directional control valve block is provided with a plurality of valve cores, and opening and closing of the valve cores of the pilot operated directional control valve block can be realized by controlling the electromagnetic pilot valve. The large-flow control valve block of the system realizes synchronism of actions of the valve cores by the same electric signal control, meets requirements of the test system for quick response, solves a contradiction that the traditional safety valve test system is limited by flow capacity and response speed of a control valve, and is especially suitable for dynamic test of safety valves with over 500L flow. The large-flow safety valve test system has simple structure, small occupation space, and reliable test results.