A heat exchanger including a temperature control assembly and a heat exchange assembly is disclosed. A heat exchange channel is formed within the heat exchange assembly. A branch channel arranged in parallel with the heat exchange channel is provided within the heat exchanger. The heat exchanger has a liquid inlet and a liquid outlet. The temperature control assembly includes a valve body. A valve cavity in communication with the liquid inlet is provided in the valve body. A gap and a second valve port are provided at a peripheral wall of the valve body. An annular protrusion is provided on an inner wall of the valve cavity. The valve body is provided with a valve core and a drive component therein.