Abstract: This paper adopted the finite element method and theoretical analysis to solve the problem of determining the maximum stress of a hook. Firstly, NX software was used to create a 3D model, and then the system was switched to the CAE module, where NASTRAN was employed to perform finite element analysis and obtain the maximum stress at the critical point of the dangerous section. At the same time, the theoretical calculation method of material mechanics was applied to solve the maximum stress, and the results from both methods were compared to analyze the sources of error. On this basis, an innovative approach was proposed to back-calculate the maximum load using the linear relationship between stress and load as well as the allowable stress value, and the result was verified through finite element analysis.Subsequently, geometric optimization was carried out based on the initial load finite element results. With the initial load unchanged, allowable stress as the target, and thickness as the variable, an optimization design was performed to reduce the weight.This combination of CAD/CAE is beneficial for improving the design and analysis efficiency of irregular parts, and reducing design and production costs.