For a V-type diesel engine, the simplification of the body model and the strength analysis of the main bearing housing were carried out. Firstly, using the model suppression method of regional suppression, a simplified scheme for the diesel engine body model is proposed, and the complex area on the body model is simplified to obtain the corresponding simplified model. Then, in the Abaqus software, the finite element analysis of the structural strength of the main bearing housing is performed on the original model and the simplified model of the diesel engine body by applying the same boundary conditions and loads to obtain the corresponding stress and strain data. Compared with the maximum principal stress of the body and the main bearing cover and the deformation of the main bearing hole of the original model , the simplified model is obtained with an error of less than 5%.