Abstract: The Ni-Cu alloy N04400 surfacing welding procedure of Q345R test plate was qualified by flux-cored wire gas metal arc welding(FCAW-G).The bending,chemical composition and metallographic structure of surfacing layer were tested according to NB/T 47014-2011《Welding procedure qualification for pressure equipment》.The test results showed that the transition layer and corrosion resistant layer were surfacing welding by using the flux cored wire of ENiCu7T0-4 with 80%Ar+20%CO2 mixed shielding gas,the corrosion resistant layer with excellent performance can be obtained and the chemical composition of corrosion resistant layer meet the standard requirements.The research in this paper provides a new process reference for Ni-Cu alloy to achieve efficient surfacing welding.