High-low temperature coolant test system for battery pack is specially used for thermal and hydrodynamic test on liquid-cooling battery pack. According to the demands of battery performance test, equipped with a variety of high performance sensors, the system can test flow rate, pressure and temperature of the battery pack coolant and can provide the temperature simulation, the pressure simulation and the flow simulation in the temperature range of -40~85℃. RS485, CAN and other communication protocols are supported, which make the communication with host computer or charging machine available.