Battery pack thermal management system

The utility model discloses a thermal management system for a battery pack, which belongs to the technical field of batteries and is designed for solving the problem that the temperature uniformity of the battery pack is inevitably poor in one of a cooling working mode and a heating working mode due to the fixed flowing direction of a secondary refrigerant. The utility model discloses a battery pack heat management system which comprises a heat exchange plate provided with a first opening and a second opening, and a pipeline connected between the first opening and the second opening is arranged in the heat exchange plate; a secondary refrigerant delivery pipe; the heat exchange plate, the secondary refrigerant conveying pipe and the reversing device form a secondary refrigerant flowing loop, and the reversing device can selectively enable a secondary refrigerant in the secondary refrigerant conveying pipe to sequentially flow through the first opening, the pipeline and the second opening or enable the seconda