Method for preparing speckles suitable for high-temperature environment

The invention discloses a method for preparing speckles suitable for a high-temperature environment. The method comprises the following steps: preparing ferric hydroxide colloid by adopting a ferric salt solution and an aqueous alkali, polishing a substrate material, removing impurities on the surface of the substrate material, placing the treated substrate material into a container with the ferric hydroxide colloid, heating to resolve the ferric hydroxide colloid, depositing generated ferric oxide on the surface of the substrate material, cooling, trimming the surface of the substrate material, carrying out heat treatment on the substrate material under high-temperature environment, and thus obtaining the speckles. The method is easy to operate, simple in used equipment, and low in cost, and the prepared speckles are suitable for performing non-contact measurement on material deformation by utilizing a relevant digital image technology under the high-temperature environment, therefore, the application prospect is wide.