The invention discloses a self-centering clamp for a special-shaped faucet. The clamp comprises at least three clamping jaws, a guiding part, a rotating part, a turning connection part, a shell and a power mechanism. A slide rod is arranged below each clamping jaw, and a positioning block is arranged on the outer side face of each clamping jaw. The guiding part is provided with a guiding groove for the slide rods to penetrate therein. A slide groove for the tail ends of the slide rods to penetrate therein is formed in the rotating part, and a shaft rod and a sliding pin are arranged below the rotating part. The turning connection part is connected with the power mechanism and is provided with a slide groove plate, a sliding groove which is obliquely formed is formed in the sliding groove plate, and the end of the sliding pin penetrates the sliding groove. The self-centering clamp is suitable for the long special-shaped faucet. A mechanism similar to a clamping jaw self-centering chuck is adopted, the clamping jaws stretch outwards at the same time, the clamping forces of all the clamping jaws are the same, and automatic centering can be guaranteed when the faucet is installed; and even though the clamping jaws clamp the interior of the faucet, polishing of the outer surface of the faucet is not affected.