Abstract: In order to avoid the phenomenon of element diffusion enrichment in the welding of dissimilar steels, this paper uses the method of pre-edge overlay welding ENiCrFe-3 transition layer to achieve a good weld of dissimilar steels, but the precipitation of carbide was found in the welded joint, and then the crystal plasticity finite element method was used to construct a crystal plasticity finite element analysis model with the addition of carbide at grain boundaries. Simulation results show that: carbide precipitation phase will have a significant effect on the stress-strain distribution within and on the grain boundaries, due to the increase in carbide content, the stress concentration increases in the region of inclusions, the three-grain intersection is the weakest region of the mechanical properties of the weld, and the stress distribution at the intersection of the grain boundaries of the three grains is asymmetric and usually the first to fail and become a source of fracture.