The outer layer is an environmentally friendly polyolefin heat shrink tube, and the inner layer is made of EVA hot melt adhesive rings and an environmentally friendly tin ring. It provides wire-to-wire splicing and the transparent outer layer facilitates clear identification of wire connection operations. Designs of this product is the tin ring welding to the cables, outer heat shrink tubes for protecting wire connections and excellent waterproof sealing function of hot melt adhesive rings on the ends of heat shrink tube. All connection protection of wires can be completed in a single step, and the simple construction method can reduce the installation cost.