The hybrid power unit integration and the design process of its device were introduced, the analysis method of strength,mode and fatigue with ANSYS was expounded, and the theoretical analysis target from CAD design to CAE verification was realized. The results showed that the hybrid unit device could carry the mounting body well and ensure the reliability and safety of the whole vehicle power transmission system. At the same time, using the design method, the design cycle was shortened, the assembly efficiency of the whole vehicle was improved, and the application of hybrid power integration technology in track construction machinery was promoted.