Pneumatic tourniquet is the most commonly used tourniquet and hemostasis method in emergency department. The specific use method is very simple: First, check the performance of the tourniquet before use and check whether there is air leakage. Second, according to the patient’s gender, age, body condition and surgery and bleeding site to choose the width and length of the cuff suitable for the application of the patient, such as female patients are relatively thin or young, then choose a small cuff, male adults choose a large cuff, children can choose the smallest children’s type of cuff. Third, the upper limb tourniquet is placed in the upper third of the upper arm, and the lower limb should be placed in the upper third of the femur, and as close to the root of the thigh as possible. Because after close to the root of the thigh, not only the hemostatic effect is good, but also not easy to damage the nerve. Fourth, before tying and hemostasis, you should check whether the local skin is broken, and try to avoid tying the pneumatic tourniquet at the broken skin. If there is a local break in the skin, first use a protective sleeve or sterilized ligature cotton ball to protect this area first, and then tie the tourniquet after protecting the limb. Fifth, try to pay attention to aseptic operation. Sixth, under normal circumstances, the air pressure in the upper extremity of adults is 40KPa and in the lower extremity is 50KPa Hg, but it varies from person to person.