PVC is synthesized by vinyl chloride through free radical polymerization. By suspension polymerization method, emulsion polymerization method and bulk polymerization method, the suspension polymerization method was mainly used, which accounted for about 80% of total PVC production. The industry generally will be PVC production process based on the method of obtaining vinyl chloride monomer, can be divided into calcium carbide method, ethylene method and import (EDC, VCM) monomer method (used to the Ethylene method and the import monomer method collectively referred to as Ethylene method). According to the different production methods, PVC pure powder is divided into: Universal PVC resin, high polymerization degree of PVC resin, cross-linked PVC resin. The common type PVC resin is formed by polymerization of vinyl chloride monomer under the action of Initiator. PVC resin with high polymerization degree is a resin which is polymerized by adding chain growth agent in the vinyl chloride monomer polymerization system, and cross-linked PVC resin is a resin which is polymerized by adding the crosslinking agent containing the diene and the poly in the vinyl chloride monomer polymerization system.