Metallographic etchant for high-entropy alloy, preparation method of metallographic etchant and metallographic etchant method

The invention relates to a metallographic etchant for a high-entropy alloy, a preparation method of the metallographic etchant and a metallographic corrosion method, and belongs to the field of metal corrosion. The metallographic etchant for the high-entropy alloy comprises nitric acid, hydrochloric acid, hydrofluoric acid, sulfuric acid and a solvent, wherein the solvent comprises absolute ethyl alcohol. By adding hydrofluoric acid, the corrosion strength of the corrosive liquid is improved, and the high-entropy alloy can be corroded better; and by adding the sulfuric acid, the corroded high-entropy alloy is clearer in grain boundary and grain, and the contrast ratio of precipitates is high. The invention further provides a preparation method and a metallographic corrosion method of the metallographic corrosion liquid of the high-entropy alloy, the applicable corrosion time range of the corrosion liquid is 5-10 seconds or above, the corrosion liquid has the characteristics of clear grain boundary and crystal