Blood glucose monitoring and management in critically ill patients constitutes an important part of intensive care. Continuous glucose monitoring (CGM) can improve the time in the target blood glucose range and reduce hypoglycemic events, and it has been widely used in patients with diabetes. Its advantages, including continuous glucose data collection, multiple glucose dynamic indicators, minimal invasiveness and reduced workload for medical staff, have drawn increasing attention from ICU clinicians. However, the clinical applicability of CGM in ICU patients remains controversial due to the critical conditions and rapid pathophysiological changes. This article elaborates on the recent progress regarding the accuracy of CGM in critically ill patients, as well as whether it can improve the quality of blood glucose control and clinical prognosis.