Using highly weather-resistant EPDM rubber sleeve expanded and assembled onto a spiral type removable plastic supporting core. Remove the supporting core after the sleeve positioned to the cable joint that requires insulation and sealing protection, the EPDM rubber sleeve will shrink onto the joint quickly and tightly. Allows to quick construction without the use of tools in narrow spaces where fire sources are not allowed. Applied to the sealing protection of overhead or buried power cable connection and communication base station cable joints with rated voltage under 1kV.