Abstract: The ANSYS simulation software has been used to analyze the bending formability of resin composite lightweight steel sheet. Because the lightweight steel sheet is composite, the outside steel sheet produces relative slipping-off change during the bending. So the inner stress-strain situation, the effect of material parameters and tool parameters, composite structure and intermediate-layer resin of lightweight sheet on slippingoff change have been analyzed. At the same time, the spring-back and searin stress situation after bending have been discussed also.