<p>Nanozyme has become a new rising star in the medical field because of its high stability, strong catalysis, ease of modification and manufacturing compared with natural enzyme. Nanozyme can regulate reactive oxygen species (ROS), such as down-regulation in inflammation and up-regulation in tumor. Nanozyme plays an important role in treatment of various diseases due to this ability. Additionally, nanozyme can corporate with traditional and novel therapies, which are of tremendous help in both therapeutic and diagnostic aspects. In this review, we summarize the classification and mechanism of action of nanozyme, and its therapeutic and diagnostic applications in various diseases, especially focusing on its potential application for inflammation related diseases, cancer, neurological disorders, cardiovascular diseseases, metabolic diseases, infectious diseases, artificial implants and biomedical detection.</p>