Objective To calculate the stress at corner using the finite element method. Methods Based on the first simulation of the finite element model, the stress contours were investigated and a relatively less gradient direction was determined. Around the corner, a rectangle with certain size was drawn on the surface of the geometry along this direction, at the same time some key points were decided on the edge of the rectangle. After several times of remeshing of this rectangle, the values of stress were investigated at the key points. When the value of stress showed a trend of convergence, a three-order spline was constructed according to these values of stress. Extrapolating was carried out at this spline, and finally the value of stress at the corner was speculated. Results A sample was used to evaluate this method and the stress of corner was 1. 46 MPa. Conclusion The extrapolating method can be used to calculate the stress of the corner.