<p>In order to solve the problem of poor formability caused by different materials and properties in the process of tailor-welded sheets forming, a forming method was proposed to change the stress state of tailor-welded sheets by covering the tailor-welded sheets with better plastic properties overlapping sheets. At the same time, the interface friction effect between the overlapping and tailor-welded sheets was utilized to control the stress magnitude and further improve the formability and quality of the tailor-welded sheets. In this work, the bulging process of the tailor-welded overlapping sheets was taken as the research object. Aluminum alloy tailor-welded overlapping sheets bulging specimens were studied by a combination of finite element analysis and experimental verification. The results show that the appropriate use of interface friction between tailor-welded and overlapping sheets can improve the formability of tailor-welded sheets and control the flow of weld seam to improve the forming quality. When increasing the interface friction coefficient on the side of tailor-welded sheets with higher strength and decreasing that on the side of tailor-welded sheets with lower strength, the deformation of the tailor-welded sheets are more uniform, the offset of the weld seam is minimal, the limit bulging height is maximal, and the forming quality is optimal.</p>