Abstract: According to working requirements of self-propelled sprayer，a kind of fork between tire and leg was designed to support the body of sprayer，and the model of fork was built based on Creo.Tires were required walk and rotate along the vertical axis.So the fork in addition to support whole body gravity，but also need to support torque.Its stress situation was more complex. In order to ensure normal work of the fork，finite element analysis using Simulate module was carried out based on Creo.Fork force was obtained from analysis result.