The morphological characteristics and stalk biomechanical properties at the dough stage of wheat were determined using the variety of wheat in the breeding process.Their mechanical responses to wind and rain loads for an individual and a group of wheat were simulated using finite element method by ANSYS.The stress and displacement of each finite element can be outputted through stress nephogram and displacement nephogram,respectively.In order to judge whether the wheat could return to its original position after deformation,elastic mechanics theory was utilized to analyze the critical load of instability under both axial rain load and transverse wind load.The large displacement situation was analyzed with large displacement elastic nonlinear theory and the numerical value was obtained by ANSYS.The results show that it is possible to apply various load types on models using ANSYS and the dynamic response can be simulated well under different rain and wind loads.The location of maximum Von Mises stress can be calculated and the variation of stress can be described clearly,which are helpful to predict the wheat lodging under wind and rain loads.