Corrosion-resistant and wear-resistant gradient coating for high-temperature working condition and preparation method thereof

The invention discloses a corrosion-resistant and wear-resistant gradient coating for a high-temperature working condition. The corrosion-resistant and wear-resistant gradient coating comprises a corrosion-resistant coating body and a wear-resistant coating body which are sequentially attached to a base body. The invention further discloses a preparation method of the corrosion-resistant and wear-resistant gradient coating for the high-temperature working condition. The corrosion-resistant coating is formed by spraying nickel-chromium-molybdenum alloy powder on the surface of a base body. The wear-resistant coating is formed by spraying nickel-chromium alloy powder on the corrosion-resistant coating; the nickel-chromium-molybdenum alloy powder comprises the following components in percentage by weight: 14.5%-16.5% of Cr, 15.0%-17.0% of Mo, 4.0%-7.0% of Fe, 3.0%-4.5% of W, less than or equal to 2.5% of Co, less than or equal to 0.08% of Si, less than or equal to 1.0% of Mn, less than or equal to 0.01% of C, le