Metallographic etchant of pure titanium and etching method thereof

The invention provides a metallographic etchant of pure titanium and an etching method thereof. The metallographic etchant comprises an etchant A and an etchant B, wherein the etchant A is composed ofthe following components by volume percent: 4% to 6% of hydrofluoric acid and 8% to 12% of nitric acid, and the balance being water; and the etchant B is composed of the following components by volume percent: 45% to 55% of hydrofluoric acid, and the balance being water. The metallographic etching method comprises the following steps of step I, etching a pure titanium specimen with the etchant Afor 55 to 65 s, then, washing the pure titanium specimen with water, and blow-drying the washed pure titanium specimen; and step II, etching the pure titanium specimen with the etchant B for 4 to 6 s,then, washing the pure titanium specimen with water in 2 seconds, and blow-drying the washed pure titanium specimen after cleaning, so as to obtain a pure titanium metallographic specimen. Accordingto the metallographic etchan