Water cooling structure of motorcycle engine

The utility model provides a water cooling structure of a motorcycle engine, and belongs to the technical field of engines. The problem that an existing motorcycle engine is poor in engine oil cooling effect is solved. According to the water cooling structure of the motorcycle engine, the engine comprises a box body, a cylinder body and a cylinder cover, an oil cooler is installed on the box body, the water cooling structure comprises a thermostat, the thermostat comprises a shell arranged on the cylinder body in a covering mode, and a water return cavity used for being connected with the water outlet end of a radiator and a water inlet cavity communicated with an upper water jacket are formed between the shell and the cylinder body. A heat exchange part extending upwards from the bottom face to the top face is arranged in the water return cavity and is columnar, a heat exchange channel is formed in the heat exchange part in the length direction, the upper end of the heat exchange channel is communicated with