Abstract: COMSOL finite element software was used to establish the model of the austenitic stainless steel micro-crack induced by stress corrosion through using the nonlinear surface wave detection. Two methods of sequential coupling and direct coupling were used to realize the coupling of stress field and acoustic field respectively. COMSOL software has strong feasibility and superiority in the simulation field of creating nonlinear surface wave detect stress corrosion micro-crack, which greatly reduces the difficulty of modeling and shortens the simulation operation time. The best parameter combination was used to research the detection of metal surface micro-cracks, and the influence of stress size, micro-crack size on the propagation characteristics of nonlinear surface waves was discussed, and the experimental verification was performed. The results show that: when the size of the micro-crack is fixed, the nonlinear response decreases with the increase of the stress applied at the boundary of the micro crack; under constant stress, the nonlinear coefficient is positively related to the depth of the micro crack, and is negatively related to the width of the micro crack. The experimental results and the simulation results are in good agreement.