EXPANSION TANK, VEHICLE COOLING SYSTEM AND VEHICLE

Disclosed is an expansion tank, including a cavity structure and a degassing flow channel, where the degassing flow channel is arranged on the expansion tank, a flow guide hole is provided on the degassing flow channel, and the degassing flow channel is in communication with the cavity structure by means of the flow guide hole; and a liquid inlet and a liquid outlet are provided at two ends of the degassing flow channel respectively and are used for being in communication with a vehicle cooling system. The expansion tank of the present application satisfies a degassing requirement, reduces usage amount of pipelines and pipe clamps, and reduces weight of a vehicle body.