Deformation prediction of convex plate by induction heating with multiple heating lines is a key technology in the research of steel plate induction heating. Based on the thermal-elastic-plastic numerical simulation of triangle induction heating of steel plate, a query program of inherent strain data for triangular induction heating of steel plate is developed. Then, the actual inherent strain distribution is loaded in the elastic finite element model, so deformation calculation of convex plate with multiple heating lines is carried out. The results show that the deflection value obtained by the elastic finite element model is consistent with the experimental value, and calculating time is short. These results indicate that the calculation process is effective and can be applied to the deformation prediction of the convex plate with multiple heating lines.