Abstract: This study aimed to systematically investigate the effect of weld seam position on forming performance and material flow law of dissimilar high-strength steel tailor-welded blanks(TWBs). Two groups of high-strength steel tailor-welded blanks, namely DP590-TRIP590 and DP590-HC420, were used as the research objects. Microstructure and microhardness distribution of the TWBs joints were analyzed. Cupping tests, deep drawing tests combined with the finite element analysis method were adopted to study the influence law of different weld seam positions on the forming performance of TWBs. The results show that the Erichsen cupping values (IE) of the two groups of TWBs are significantly lower than those of the individual base material. When the weld seam is centrally located, the lowest IE value is obtained, and the crack propagates toward the two sides of the base materials along the direction perpendicular to the weld seam. When the weld seam deviates from the center, the IE values of both groups of TWBs in the cupping test increase, indicating that bulging capacity is enhanced. Consequently, the fracture location shifts to the side of the base material with a larger proportion. When the proportion of DP590 base metal is larger than 50%, the overall bulging capacity of the welded blank is increased. Conversely, when the proportion of DP590 part is lower than 50%, the overall bulging capacity of the TWBs depends on the HC420 or TRIP590 base material. In addition, the deep drawing of both groups of TWBs can be successfully completed and crack dose not occur in weld seam, their material flow behavior during deep drawing is similar to that of the individual base material, and the weld seam exhibits almost no offset during the forming process.