The invention provides an anti-corrosive coating for a high-precision probe for flange flaw detection. The coating is prepared from a component I, a component II and wear-resistant metal powder in a mass ratio of 1: 1: 1, wherein the component I is formed by mixing a component A and a component B in a ratio of 0.5: 1.5. The anti-corrosive coating is prepared through the following steps: firstly, rare earth is divided into three parts, the amount of the first part is 2/5 the total amount of the rare earth, the amount of the second part is 2/5 the total amount of the rare earth, and the third part accounts for 1/5 the total amount of the total rare earth; during preparation, the first part of rare earth is mixed with the component I, the second part of rare earth is mixed with the componentII, the mixed component I and component II are mixed with the third part of rare earth and metal powder a, and the anti-corrosive coating is obtained.