Nanozymes are nanomaterials with enzymatic catalytic activities. Compared with natural enzymes, nanozymes have many advantages, such as low price, simple preparation process, good stability and high cycle utilization. Previous studies have mainly used nanozymes for detection applications, including the detection of ions, small molecules, nucleic acids, proteins and cancer cells. With the deep understanding of nanozymes, it is found that they also have great potentials in disease treatments. This review will introduce the latest research progress of nanozymes in the fields of bacterial infection, inflammation, cancer and neurodegenerative diseases.