The invention discloses a convenient and fast high-temperature shell clamping tool which comprises a mechanical arm, a guide block, a radial telescopic mechanism and two clamping claws. The mechanical arm is a rod-shaped component with the center axis arranged flatly, and the guide block is fixedly connected to the front end of the mechanical arm. Each clamping claw is a rod-shaped component and is parallel to the center axis of the mechanical arm, and the two clamping claws are symmetrically arranged above and below the center axis of the mechanical arm. The clamping jaws are connected with the guide block through the radial telescopic mechanism. According to the further improvement, clamping is achieved by driving a transmission rod through an air cylinder. According to the convenient and fast high-temperature shell clamping tool, clamping is convenient and fast, reliable and safe, and efficiency is high.