Abstract: Aiming at the welding defects that stress concentration easily occurs in the welding process of large marine exhaust valves, the ABAQUS finite element software was used to numerically simulate the stress and deformation of the exhaust valve in surfacing high-strength alloy powder. In order to take into account the nonlinear changes in the material, the melting point was used to define different states of the material, and write it together with the material parameters into the UMATHT subroutine. The results show that the calculated residual stress values based on the UMATHT subroutine have a better fitting degree with the experimental results, and the residual stress is strongly influenced by the material itself, and the stresses of the thickness direction and the axial direction are roughly symmetric with the center of the weld. The overall deformation of the weld is larger than that of the base material, but the deformation is small, which is mainly located at the middle part of the weld.