A valve assembly, a heat exchange assembly, and an oil temperature regulation system for a gearbox. The heat exchange assembly comprises a heat exchange core body (10), the valve assembly, an adapter, and a mounting plate (101) that is fixed to the heat exchange core body (10). The valve assembly is disposed at a second channel (1052) of the heat exchange core body (10) or partially located at the second channel (1052). The valve assembly is provided with a first valve port (31) and a first notch (13). The heat exchange core body (10) also comprises a through channel that is in communication with a fourth port (1012). When the first valve port (31) is opened, a third port (1011) sequentially passes through a first channel (1051), the second channel (1052), the first notch (13) and the first valve port (31), and is in communication with a fourth port (1012). When the first valve port (31) is closed, the third port (1011) sequentially passes through the first channel (1051), the second channel (1052) and the first notch (13), and is in communication with a fifth port (1033). The heat exchange assembly is integrated with the valve assembly, and by arranging a spring made of a memory alloy in the valve assembly, the structure is simple, the volume is small, and the response speed is high.