Degradable plastic bags are the abbreviation of all kinds of biodegradable plastic bags. At present, with the development of science and technology, all kinds of materials that can replace traditional PE plastics appear, including PLA, PHAs, PBA, PBS and other polymer materials. It can be a perfect substitute for the traditional PE plastic bag. The application of environmental plastic bags has been widely used at present: supermarket shopping bags, fresh-keeping bags, film and so on are used in large scale in China. In Jilin Province, the traditional plastic bags have been replaced by PLA (polylactic acid) in the province, and good results have been achieved. In Sanya, Hainan Province, the starch based biodegradable plastic bags have also been used in supermarkets, hotels and other industries.