Mechanical ventilation is widely used in critical care medicine and anesthesiology. It is an important respiratory support for critically ill patients and patients undergoing surgery under general anesthesia. Either prolonged or shortened duration of mechanical ventilation may cause adverse effects. Therefore, it is of importance to accurately evaluate the time to weaning. Point‑ of‑care ultrasound is widely used during the withdrawal of mechanical ventilation, due to its non‑invasive nature and high efficiency. This paper introduces the research progress on respiratory muscle ultrasound, lung ultrasound and cardiac ultrasound in patients during the withdrawal of mechanical ventilation from the aspects of respiratory muscle function and cardiopulmonary function which lead to weaning failure. It has become a trend to guide the withdrawal of mechanical ventilation through multi‑organ combined with ultrasound indicators.