At present, most of the power cables running online are PVC sheathed cables without thermal insulation, flame retardancy and fire resistance. These cables are arranged in the tunnel, cable well and the incoming line of power transformation and distribution station. In case of fire, it will lead to secondary fire. In order to carry out fire prevention treatment for PVC sheathed cables used in the above occasions, the methods of coating fire-proof coating, winding fire-proof tape or asbestos rope on the outer sheath of cables are mostly adopted at present. However, in the above occasions, the cables are densely arranged and the space is narrow, which makes the construction very difficult or even impossible.

      The utility model relates to a cable heat insulation fireproof sleeve, which comprises a sleeve made of organic refractory material, and an opening is arranged along the axial direction on the pipe wall of the sleeve; A lower lapping tongue is arranged along the edge of the tube wall on one side of the opening, and an upper lapping tongue is arranged along the edge of the tube wall on the other side of the opening; The upper lap joint tongue is connected with the lower lap joint tongue through a connector arranged along the axial direction after lap joint; The pipe wall of the casing is provided with a plurality of heat insulation through holes along the axial direction, and the plurality of heat insulation through holes are evenly arranged along the circumference of the casing section.

      The connecting piece is composed of a bottom plate, two or more studs fixed on the bottom plate along the axial direction, and nuts connected with the studs; A plurality of holes for stud penetration are arranged along the axial direction on the upper lap tongue and the lower lap tongue.

      The utility model has the advantages that a plurality of heat insulation through holes are arranged in the casing wall along the axial direction. Because the heat conductivity of the air is less than that of the organic refractory wall, this not only improves the heat insulation performance of the casing wall, but also greatly reduces the manufacturing cost of the casing and saves the consumption of raw materials. The sleeve is arranged in an axial opening structure, which greatly facilitates the installation and operation of cables arranged in tunnels, cable wells and power transformation and distribution stations.