RESUMEN
Since December 2019, COVID-19 had spread many countries, attracting high attention from the world. Its infectivity is strong, harm is big, at present there is no definite effective antiviral drug. Recently, the national health commission released the latest "new coronavirus pneumonia diagnosis and treatment program (trial seventh edition)", which for the first time proposed immunotherapy program based on Tocilizumab (TCZ). In this paper, firstly, a review of articles on the treatment of immune system diseases with TCZ at home and abroad was conducted to analyze the effectiveness of TCZ in the treatment of severe and critical COVID-19. Then, from the safety point of view, the drug interactions, drug use in special population, adverse reactions and medication precautions were presented in detail, which can be used as a medication reference for the treatment of COVID-19 severe and critical patients.