Abstract: Objective Welding is a necessary process in the manufacturing process of nuclear waste storage tanks, but residual stress and deformation generated in the process have a great impact on strength and safety reliability of storage tank itself. Therefore, it is necessary to discuss variation of residual stress and deformation during plasma arc welding of nuclear waste storage tanks. Methods Influence of welding current on residual stress and deformation in plasma arc welding of 316L nuclear waste storage tanks is discussed by means of experiment and numerical simulation. Results The results show that with the increase of welding current, gradient of equivalent stress distribution on both sides of weld decreases, and stress area of 200～400 MPa increases significantly. The peak stress and stress distribution of transverse residual stress increase significantly with the increase of welding current, while longitudinal residual stress is less affected by welding current, and the peak values of transverse and longitudinal tensile stress on the inner surface are higher than those on the outer surface. Under different welding current conditions, the overall maximum deformation and the maximum deformation in the Z direction are concentrated on both sides of cylinder, and longitudinal deformation trend shows the law of shrinking toward the middle of cylinder. Conclusion By comparing temperature history, residual stress and welding deformation with the measured results, it is proved that the simulation results are in good agreement with the measured results.