To elucidate the mechanisms of laser bending and edge effect and its control strategy, we constructed a laser thermoforming model of stainless steel-low carbon steel-stainless steel laminated metal composite plate using finite element analysis software ABAQUS. The temperature field and stress and strain fields between composite plates in laser scanning were quantitatively analyzed . The results from our study show that the difference in thermal conductivity between stainless steel and low carbon steel results in the formation of a bending angle. The main cause of the edge effect is the nonuniform distribution of temperature and plate constraints along the heating path; repeated heating improves surface temperature distribution and increases forming accuracy. Four new scanning strategies are proposed; these strategies reduce the relative change rate of surface temperature by 36% and the relative rate of change of the bending angle along the heating line by 51.8%, which improves the forming precision. Our results provide a guideline for the selection of scanning strategy for composite metal plate bending formation in industrial production.