Through the failure analysis of the after-sales fault parts of the engine oil cooler and filter assembly, the design focus of the filter seat, filter, cooler and other core parts is clear, the design of cooler and filter assembly is completed, and the design failure risk is reduced. The finite element simulation software is used to analyze the mode and vibration, as well as the CFD (Automated Fluid Dynamics) fluid dynamics analysis. The simulation results show that the natural mode meets the vibration requirements of the whole machine. Under the given vibration conditions, the stress in the front-back, left-right and vertical directions is less than the fatigue limit, and the strength of the filter seat meets the requirements. Through CFD simulation analysis, the oil pressure drop also meets the requirements. The vibration test, oil pressure drop test and static pressure burst test were carried out on the sample of the engine oil cooler and filter assembly. The results met the design requirements of the main engine plant, verified the accuracy of the finite element model and simulation analysis, and provided a reference for the design of the mechanical filter assembly in the future.