Abstract: Deoxyribozyme is a kind of DNA molecule with catalytic activity. It can be selected by systematic evolution of ligands by exponential enrichment (SELEX). This review focuses on the classification, selection and main applications of deoxyribozymes. According to the catalysis, deoxyribozymes can be classified into cleaved, ligated, phosphorylated and other types. Nowadays the cleaved and ligated types account for a large proportion, and nucleic acids are the main substrates of deoxyribozymes. Biotin-streptavidin method or polyacrylamide gel electrophoresis is often used to separate the catalytic DNA in selection of deoxyribozymes. Deoxyribozymes have good application prospect in metal ion detection, gene therapy and DNA molecular encryption system.