The invention relates to the technical field of manufacture of a silicon carbide device, and especially relates to a preparation process of a silicon carbide groove type device. The invention provides a method for etching silicon carbide. The method comprises the following steps: the step B, growing a mask layer on a surface of a region, where etching is not needed, on the same plane as a region where the silicon carbide needs to be etched; the step C, etching the region where the etching is needed, and the obtaining a silicon carbide gate groove; the step D, annealing the gate groove by using gases, wherein the gases comprise a gas containing chlorine, an oxidizing gas and an optional carrier gas, and the carrier gas comprise a helium gas, a neon gas, an argon gas, a krypton gas and an xenon gas; and the step E, removing the mask layer.