Ventilator-associated pneumonia (VAP) is one of the most common infectious diseases in patients undergoing mechanical ventilation in intensive care unit (ICU). Although the use of closed sputum suction tube for sputum suction is the most common nursing measure for patients with tracheal intubation in ICU, and it is also an important measure to reduce the occurrence of VAP, the existing clinical technology still needs to use external flushing solution for humidification and flushing. In the process of use, the flushing operation has the risk that the amount of flushing fluid cannot be controlled, resulting in a large amount of flushing fluid entering the patient's airway, causing the patient to suffocate. The sputum attached to the wall of the sputum suction tube cannot be completely flushed, and the prolonged retention of the sputum leads to the proliferation of colonized bacteria, aggravating the infection of patients. Repeated pipe flushing not only increases consumables, but also increases the workload of medical staff. For this reason, the author has designed a fully enclosed sputum suction tube flushing device, which has obtained the National Utility Model Patent of China (patent number: CN 2019 2 1198740.5). This device is an integrated design, and the materials used for sputum suction, humidification and flushing are fully enclosed, without air exposure, and can be operated strictly without bacteria. Pulse flushing with syringe can clean the sputum attached to the inner wall and reduce the incidence of VAP. The volume of flushing fluid can be effectively controlled during use to ensure patient safety and reduce waste. It is worth popularizing and applying in clinical practice to optimize the operation steps and reduce the workload of medical staff.