A FEM model, based on the structural characteristics of laminated clad metal sheets (LCMS) containing defects, was developed to study the variations of temperature field in the flexible forming using plasma arc. The typical LCMS Q235A/1Cr18Ni9Ti was selected as the sample, and the effects of different defects in the bonding interface on the temperature field were analyzed. The results show that the peak value of temperature containing defect is 107 oC higher than that without defect under the same processing parameters. The peak values of temperature and temperature difference increase with the increasing of defect size, but decrease when the location of defect is far away from the heating surface of LCMS. Compared with spherical defect, cubic defect has more power to impede heat conduction along the thickness direction of LCMS.