Abstract: In order to improve the surface quality and wall thickness uniformity of the formed parts, a method of incremental forming of double-layer sheets was proposed. Taking typical conical parts as the research object, 5052 aluminum alloy sheet as the target sheet, and 304 stainless steel sheet as the auxiliary sheet, the surface roughness and wall thickness distribution of the formed parts were analyzed experimentally. The influence of auxiliary sheet on the surface quality and wall thickness uniformity of the formed parts was discussed. The results show that the surface quality of parts of single-layer sheet and double-layer sheets incremental forming is significantly different. Under the condition of the target sheet thickness ≥ 0.6 mm, the parts with better surface quality can be obtained by two-layer sheets incremental forming. The thickness of the auxiliary sheet has an effect on the surface roughness of the formed parts, and the appropriate thickness of the auxiliary sheet can improve the uniformity of wall thickness distribution of the formed parts and increase the minimum thickness.