The finite element software ABAQUS is a three-dimensional analysis software integrating various functions. It can carry out systematic analysis of complex structural mechanics and traditional solid mechanics, simulate some very complex models, and deal with highly nonlinear problems. Not only ABAQUS can carry out finite element analysis for the mechanics of single part and multi-part system, but also can carry out systems-level analysis and research.When finite element analysis is carried out on all bolt joints of the assembly, in order to simplify the calculation, the model is usually simplified and the contact surfaces of the two connected parts are connected together. In this case, the results of simulation analysis must be greatly different. In this paper, ABAQUS finite element analysis software is used to compare the stress on the joints before and after the simplified bolt connection and the deflection changes before and after the simplified bolt connection, and provide some theoretical basis for the application of the structural form of bolt connection.1. Model constructionNo matter in what kind of large equipment, the structural form of bolt connection is inevitable. In this paper, two connection plates connected by bolts are used as the analysis object, and one of them is used as the loading plate