The invention relates to a special clamp for drilling a blade tip centre hole and used for a blade. The special clamp is suitable for drilling blade tip centre hole of the blade with a plurality of sizes and has wide range of application. The special clamp comprises a jig body, an upper drill plate, a drill bush. The jig body is internally provided with a locating base; the two sides of the locating base and the side wall of the jig body are provided with a side locator key; the special clamp is characterized in that: the two side of the upper drill plate is embedded on the side locator key; the bit bush is inverted on the upper drill plate; the exit and the opening of the bit bush are arranged on the bottom of the upper bit panel; the jig body, the locating base and the upper drill plate have the same centre.