Abstract: Intensive care unit acquired weakness (ICUAW) is a critical disease in patients in the ICU. ICUAW often involves limb muscles and respiratory muscles, resulting in difficulty in offline difficulties, prolonged hospital stay and increased mortality, which seriously affects the prognosis of patients in the ICU. Mechanical ventilation, sepsis, multiple organ failure and systemic inflammatory response syndrome (SIRS) were the common causes of ICUAW. Parenteral nutrition, neuromuscular blockers and the use of large amounts of corticosteroids, braking, etc., can also cause ICUAW. At present, there is no golden standard and treatment strategy for early diagnosis of ICUAW. This paper reviewed the research progress of ICUAW in order to deepen the clinical understanding of ICUAW and improve the diagnosis and treatment ability of clinicians.