7-ACA is the key intermediate of cephalosporin and has become the protagonist of the international antibiotic market. According to the sales volume, β -lactam antibiotics, mainly cephalosporin and penicillin, have the fastest development, accounting for about 70% of the world antibiotic market.In recent 10 years, the development of cephalosporin antibiotics is very amazing, new varieties have appeared, such as cefaclor, cefuroxime sodium, ceftin and so on. At present, the total number of cephalosporin production is more than 50, and the clinical commonly used varieties of cephalosporin are also more than 30. It is well known that any cephalosporin is a semisynthetic product, which is formed by condensation of 7-ACA, the lysate of fermented cephalosporin C, and chemical side chain.Therefore, 7ACA is undoubtedly the key intermediate for the synthesis of various cephalosporins. If there is no 7-ACA raw materials, all cephalosporins production will become "cooking without rice". Some developed countries in the pharmaceutical industry attach great importance to the research and production of 7-ACA.