KCMF-type pressure-expansible insert seal

The invention discloses a KCMF-type pressure-expansible insert seal, comprising a seal module sleeving a hollow cylindrical tube. A thorn structure, a radial through hole and a radial threaded blind hole which are integrated are provided in the outer surface of the hollow cylindrical tube in order from middle to bottom; the outer diameter of the hollow cylindrical tube below the radial through hole is greater than that of the hollow cylindrical tube above the radial through hole, and a junction between the upper and lower portions of the cylindrical tube is provided with a slope; a pressure ring, a rubber tube, a support ring, a limiting ring, a positioning ring and a piston sleeve the hollow cylindrical tube sequentially from the seal module to bottom. The support ring is fixedly connected with the limiting ring through a safety shear pin; the inner wall of the positioning ring is provided with triangular teeth, and the outer wall thereof is provided with trapezoidal teeth; the piston is movably connected with the hollow cylindrical tube through a limiting pin. When slightly corroded and abraded, the sealed tube can be sealed by hydraulic pressure, and unsealing is achieved by lifting up a string; the KCMF-type pressure-expansible insert seal is reusable and suitable for oilfield separate layer water injection or oil injection.