As a special cross-discplinary research frontier, nanozyme, which is capable of accomplishing desirable enzyme-mimicking catalytic performance based on nanomaterials, has attracted great attentions from the scientific community in recent years. The research on nanozyme is becoming a rapidly emerging field since magnetic nanoparticles with intrinsic peroxidase-like activity was first reported in 2007. The unique physicochemical properties of nanozymes at nano-level endow them with excellent catalytic performance for various applications, such as cancer theranostics. In this review, we highlight the recent developments of catalytic chemistry in advancing the development of nanomedicine for diverse nanozyme-based oncological applications, and the current challenges and future developments of nanozymes are also discussed for their further clinical translations. It is highly expected that this novel nanozyme and corresponding high catalytic performance in cancer imaging and therapy would significantly promote the generation of new subdiscipline of nanomedicine by rationally integrating catalytic chemistry with clinical theranostic nanomedicine.