Compressed air is widely used in medical institutions and is known as life support system. However, the quality of compressed air, especially the microbial content, has not been attracted extensive attention. In this paper, preparation, current domestic and foreign implementation standards and existing problems, purification measures, as well as literatures relevant to microbial monitoring technology of compressed air were summarized, aiming at clarifying the contamination sources, control strategies and monitoring methods of compressed air, so as to provide reference for performing future monitoring research as well as formulating standards and specifications.