Abstract: In view of the problem that the wet clutch of the continuously variable transmission of large tractors often fails in operation, which leads to the failure of the tractor in normal operation, the structural principle of the wet clutch of the continuously variable transmission is analyzed.The main forms of failure of wet clutch are expounded.The failure mechanism of wet clutch is analyzed in detail from the mechanical system, cooling and lubrication system, oil pressure control system, electronic control system and other aspects.It provides a reference for the optimization design of the wet clutch of the large tractor continuously variable transmission.