The residual stresses induced by using self-drilling screws on polycarbonate plates were investigated by the hybrid method which incorporates the digital photoelastic method and finite element method (FEM). Different types of screws lead to different photoelastic fringe patterns, which provide the boundary conditions needed in the numerical simulation. By changing the two main parameters (pressure and temperature), the FEM results can be matched well with the experimental results for drilling at 0 o tilt angle. For drilling at other tilt angles, the photoelastic fringe patterns provide useful information for failure analysis.