Through the operating cycle analysis of a loaders, the offset loading coefficient was proposed to accurately compute the force of loaders.In this new method, upright loading was considered as a special instance of offset loading.The force analysis of offset loading and upright loading was unified into the same continuous function. And then the stress changing trend of the lifting arms could be analyzed quantificationally by the aid of finite element software.It is shown that the position damaged greatly may be the joints between lift arms and bucket during the offset loading.But the offset loading with a certain extent can not influence the working equipment greatly.CAE model is improved based on the experimental results and the experimental results show the validity of the improved CAE model.