Large-scale steam turbine welding rotor has the characteristics of high material strength,large wall thickness,narrow groove gap,high degree of restraint,multi-layer multi-channel welding and different phase transformation of weld and base metal resp-ectively,and the residual stress distribution is very complicated. An axisymmetric finite element model is established for the annular25 Cr2 Ni4 Mo V welding simulation specimen. The residual stress and deformation of welding and heat treatment are studied and compared with the measured results. The results show that the simulation data and the experimental data are well fitted from the distribution trend and the peak position,and the stress distribution is "Pull-pressure-pull".