The invention relates to a leakage blocking device with pressure, in particular to a high-temperature and high-pressure leakage blocking clamp tool with pressure, which mainly solves the technical problems that the traditional leakage blocking clamp tool with the pressure is too large and is difficult to implement, or the leakage block quality can be influenced because of the deformation of the clamp tool. The high-temperature and high-pressure leakage blocking clamp tool is formed by two simulated cylinder flanges through butt joint, wherein the two simulated cylinder flanges cover leakage equipment and are tightly fastened through screw bolts, a structural sealing cavity is formed between the inner walls of the simulated cylinder flanges and the leakage equipment, and a groove is arranged on the contact end surface of the flange and the leakage equipment to form a sealing glue sealing and blocking cavity. A plurality of isolation valves are arranged on the structure sealing and blocking cavity, and a plurality of glue injection nozzles are arranged on the sealing glue sealing and blocking cavity. The contact end surfaces of the simulated cylinder flanges and the leakage equipment are in interference fit with the leakage equipment, and in addition, the flange contact end surfaces are in saw tooth shape. The high-temperature and high-pressure leakage blocking clamp tool is applied to the leakage treatment of high-temperature and high-pressure equipment.