Sleep disorders are prevalent in patients in the intensive care unit (ICU)， the incidence is about 14%‒50% as reported. Non⁃drug and drug treatments are all important for critically ill patients suffering from sleep disorders. The characteristics of sleep disorders in critically ill patients as well as the adverse effects of sleep disorders, the influencing factors of sleep disorders, the methods of sleep monitoring, and the current treatment for sleep disorders were described in this review. Further clinical research should focus on improving sleep quality and outcomes in critically ill patients.