Abstract: The 1000 MPa grade Ni-Cr-Mo deposited metal was prepared by metal active-gas welding and tungsten inert gas welding respectively.Optical microscope(OM), scanning electron microscope with energy spectrum (SEM), transmission electron microscopy(TEM), were used to characterize the microstructure of the deposited metal. The mechanical properties of the deposited metal were tested by tensile, oscillometric impact and microhardness testing.Exploring the effect of welding method on the strength and toughness mechanism of 1000 MPa grade Ni-Cr-Mo deposited metal.The results show that the final weld microstructure of the deposited metal prepared by different welding methods consists of lath martensite, lath bainite, combined bainite and retained austenite. TIG welding deposited metal is mainly lath martensite, MAG welding deposited metal is mainly bainite-like microstructure. The width of columnar crystals in MAG weld deposited metal is larger than that in TIG weld deposited metal, and the number and density of non-metal inclusions in MAG weld deposited metal are larger than that in TIG weld deposited metal; The different microstructure lead to a large difference in mechanical properties, the both tensile strength reached 1080 MPa, yield strength there are differences: where TIG welding 1008 MPa, MAG welding 827 MPa; AKV (−50 ℃) difference is obvious: TIG welding 95 J, MAG welding 51 J, TIG welding deposited metal strength and toughness match better.