A polyurethane radical composite material(PU/P(VC-VAC)) was synthesized by reaction of hydroxyl Vinyl chloride-acetate copolymer(P(VC-VAC))and PU.The experimentation and study showed that fine synergism could be produced between hydroxyl P(Vc-Vac) and PU molecules,So the composite material not only is of good electricity insulativity,mechanical behavior,but also high viscosity and fast safe character,and so on.The composite material can be used in the in-situ fast insulation enwrapping of broken wire and cable as well as the in-situ fast repair of conveyor belt in mine.