New application requirements and performance index of envelop material were put forward according to the development status of our materiel storage and moistureproof envelop technology. The ways to improve barrier performance and integrated protection performance were studied. According to performance requirement, PVDC was selected as barrier layer of envelop for its excellent overall performance. Coextrusion blow molding and dry composite processing technology was first applied to make composite of PVDC and TPU. PVDC composite envelop material was manufactured, which has high barrier performance, good flame retardance, and light weight.