In general, errors by mechanical and thermal deformation are resulted from the cutting forces and heat generation in cutting zone, respectively, while in machining operation. In the case of a laser integrated machine, which is used to process difficult-to-cut materials, High material removal temperature by laser preheating produces greater thermal deformation errors than that of conventional machines. However, there are difficulties in thermal analysis because a laser heat source has a very small input area and a large energy density and represents a sudden change in temperature due to its movement. In addition, it takes a long time to predict the surface temperature distribution of workpiece in existing analysis methods. Therefore, this study is aimed to predict such deformations caused by laser beams and machining processes using large-area analysis method which can reduce computation time.