The process research and development of EPP material ontology process began in the 1960s. In 1964, the American Dart company adopted the kettle reactor to build the first industrial production device of polypropylene in the world. Since 1970, Japanese sumitomo, Phillips, American EI Psao and other companies have implemented the industrial production of polypropylene liquid polypropylene. Compared with solvent slurry method, using liquid propylene ontology method to aggregate has not use inert solvent, reaction system in high monomer concentration, polymerization rate, high catalytic activity, high conversion rate of polymerization, more reactor production capacity of space and time, low energy consumption, simple process, less equipment, low production cost, less "three wastes"; It is easy to remove the polymerization heat and simplify the removal of thermal control, which can improve the polymerization of the unit reactor. It can remove the low molecular weight and the catalyst residue which have bad influence on the properties of the product, and can get the advantages of high quality products. The deficiency is that the reaction gas needs to be gasified and condensed to circulate back to the reactor. The high pressure liquid hydrocarbon material in the reactor is large and potentially dangerous. In addition, the ethylene concentration in the reactor can not too high, otherwise in the reactor to form a single gas phase, makes it hard for the reactor, operation of the ethylene content in the copolymer obtained product won't be too high.