Since extracorporeal membrane oxygenator (ECMO)has been utilized to save countless lives by providing continuousextracorporeal breathing and circulation to patients with severecardiopulmonary failure. In particular, it has played an important role duringthe COVID-19 epidemic. One of the important composites of ECMO is membrane oxygenator, and the core composite of the membraneoxygenator is hollow fiber membrane, which is not only a place for bloodoxygenation, but also is abarrier between the blood and gas side. However, theformation of blood clots in the oxygenator is a key problem in the usingprocess. According to the study of the mechanism of thrombosis generation, it wasfound that improving the hemocompatibility is an efficient approach to reduce thrombusformation by modifying the surface of materials. In this review, the medical application and the correspondingmodification methods (surface property regulation, anticoagulant grafting andbio-interface design) of hollow fiber membranes in ECMO are classified anddiscussed, and then the research status and development prospects aresummarized.