Protective method of through holes on thermal sprayed surface

The invention relates to a protective method of through holes on a thermal sprayed surface. A protective wall made of a metal material can bear the temperature of the spraying flame flow, so that a deformation phenomenon does not happen and the protective wall is not molten; after being sprayed, a coating of the protective wall does not form an integral coating with a coating on the sprayed surface, so that the protective wall is convenient to dismount. By designing a special-purpose protective wall, the protective method disclosed by the invention achieves the purposes that good high temperature resistance is achieved, and the coating is not damaged while being dismounted; moreover, the protective wall can be recycled, so that production cost is lowered and production efficiency is improved.