The utility model relates to a dust-proof cover for a percussion drilling, which belongs to electric tool accessories. The utility model is composed of a fixing clamp and a cover body, wherein, the cover body is composed of a spiral spring framework, a cover film made of rubber or plastic or cloth, and an elastic band which can be frapped and attached to a percussion drilling. The cover film is transparent, which is better. The utility model which is fixed on the percussion drilling can prevent dust dispersedly flying when the percussion drilling is used to work, and the dust is concentrated in the dust-proof cover to be dumped. The utility model avoids the dust from polluting parts of human eyes, heads, necks, etc., and ensure workmen's health. When the percussion drilling is used for vertically and upwards working, the utility model is more important. The utility model can be widely used on the percussion drilling, hammer drillings, electric hammers and other electric tools.