Abstract: In order to obtain the mechanical properties of DP980 dual-phase laser welded joint, samples containing different sections of welded joints were prepared and combined with the mixing rule to obtain the mechanical properties of each area of the joint, and finite element simulation verification was carried out to analyze the deformation and failure of the longitudinal joint. The results show that the load-displacement simulation curves of the sample joints in different zones are consistent with the experimental curves. The load-displacement simulation of the longitudinal joint is close to the experimental curve, and the simulated fracture location is consistent with the actual fracture location. The failure mode of the longitudinal joint extends from the center of the weld zone to both sides to the base metal zone. The macroscopic fracture morphology of the joint shows equiaxed dimples distributed in the weld zone, the softened zone and the base metal zone. The joint as a whole presents a ductile fracture mode.