When using a lower extremity tourniquet, first of all, it should be tied to the correct position. In lower extremity surgery, it should be tied to the upper middle 1/3 of the thigh, and the lower extremity should avoid direct compression of the femoral artery when tying the tourniquet. The normal value of pressure should not exceed 80 kPa for adults and 35 kPa for children, but the most appropriate pressure for a tourniquet should be adjusted according to the patient’s blood pressure, which is high, but should not exceed the limit, below 80 kPa for adults and below 35 kPa for children. For the lower extremities, the tourniquet should not be used for more than 90 minutes. If the tourniquet needs to be used for a longer period of time, it should be loosened for 15 minutes and then inflated and pressurized, and during the whole process of applying the tourniquet, a nurse or anesthesiologist should monitor the patient’s blood pressure and pay attention to the time of applying the tourniquet.