By calculating the torque of tractor wheel bolt,this paper puts forward the key technical points that should be paid attention to in the design,and applies the torque value that meets the requirements to the current production by checking and calculating,has carried on the follow-up market validation.Through market reflection:the torque value after switching conforms to the user's work demand,there is no bolt looseness,fracture and so on,the design calculation not only improves the reliability and safety of the tractor machine,and for the follow-up research and development to provide a certain reference.