The invention discloses a nickel chromium alloy for a sealing face of a nuclear power valve. The nickel chromium alloy comprises the following components in percentage by weight: 26.0-28.0 percent of chrome, 2.0-2.5 percent of silicon, 1.1-1.3 percent of boron, 4.5-5.5 percent of molybdenum, 3.0-4.0 percent of tungsten, 0.9-1.1 percent of carbon and the balance of nickel. Meanwhile, a coating layer is prepared by a laser cladding technology so as to obtain a sealing face coating layer of a nickel-based alloy nuclear power valve, which has the following relevant parameters: the rigidity is HRC42-46 which is slightly higher than HRC39-43 of a Stellite-6 cobalt-based alloy coating layer; the tissue grain fineness number of the coating layer is 11-12 grades which is superior to 9-10 grades of a general plasma jet welding layer and 8-9 grades of a flame resurfacing welding layer; and the width of a combination band of the coating layer and a basal body is 10-30 micrometers which is superior to 80-120 micrometers of a plasma jet welding combination band and 200-300 micrometers of a flame resurfacing welding combination band.