In laser bending forming, the warping deformation influences the forming accuracy. Based on ANSYS software and electron microprobe, process of the warping deformation for stainless steel-carbon steel composite plate including interfaces bended by pulsed laser was simulated using a multi-layered finite element model (FEM) in single-pass scanning. By simulating temperature field, stress field, residual stress distribution and the free end deformation of the composite plate, the process and the reason of warping deformation were analyzed. The results show that during laser scanning, the uneven rate of the highest temperature on the scanning line is 18.33%, which is influenced by initial temperature and edge effect. After 0.2 s heat conduction and heat loss, heat accumulation phenomenon appears in middle area, which leads to warping deformation caused by increased thermal stress. Simulation results of the residual stress from scanning line to free end show that, warping force within the region and constraint counterforce at the edges of the region are produced, warping deformation matches both the magnitude and direction of the simulation result. The max error of warping line between the experiment and simulation is 3.90% and the error of chordal height is 3.33%, which provids the calculation basis for better bending angle control of the composite plate.