The CRISPR system is an emerging gene editing technology. It is an immune response system that exists in some bacteria. It uses the protein encoded by the Cas gene to efficiently recognize and cut the foreign DNA that enters the cell， protecting the bacteria themselves from Exogenous gene infringement. The CRISPR system is mainly used for targeted knock-in and knock-out of genes. The system has the advantages of simple operation and wide application range， and has been widely used in various microorganisms， animals and plants. Among CRISPR systems， type II CRISPR system is the most widely used system and is currently a research hotspot. It includes CRISPR/Cas9， CRISPRa and CRISPRi technologies. Since CRISPRa technology is currently less used， this article reviews the current research status of CRISPR/Cas9 and CRISPRi technologies in microorganisms， and prospects the future development of the two technologies.