The patient was a 50-year-old male, 60 kg. He was admitted to the emergency room 5 hours ago due to a car accident and was diagnosed with 1) left clavicle stem fracture; 2) left tibia and fibula fracture with N-fossa vascular injury; 3) left second metacarpal fracture; 4) 3rd and 4th lumbar spine fracture; and 5) 3rd and 4th rib fracture. Proximal tibial fracture incision and left N artery exploration for vascularization were proposed. After admission to the operating room, a puncture site was identified 2 cm below the inguinal ligament of the left extremity at 1 cm lateral to the femoral artery. A nerve stimulator and a 22G short bevel stimulating needle were used to localize the femoral nerve through the puncture point. The initial current was 2 Hz and 1 mA, and when there was a contraction of the quadriceps muscle with knee throbbing, the stimulating current was gradually reduced to 0.3 mA, and there was still muscle contraction. 2 ml of local anesthetic (0.5% ropivacaine) was injected, and a total of 25 ml of local anesthetic was injected after no abnormal reaction and no return blood was drawn back, while pressure was applied to the injection point inferiorly. After posterior turning, the needle was inserted at the midpoint of the line between the femur and the sacral fissure (using a nerve stimulator). 20 ml of 0.5% ropivacaine was injected in the same way after the contraction of the gastrocnemius muscle. 20 minutes later, the operation was started after being convinced that the block was complete. The patient was circulatory and respiratory stable during the operation and was sent to the ward after the operation. The patient was followed up postoperatively, and 16 hours after anesthesia the patient began to feel slight pain in the surgical wound. Discussion: (1) The effect of perfect local anesthesia on the patient’s circulation and respiration is much less than that of intralesional and general anesthesia, and also the suppression of the patient’s immune system is lighter. Compared with other anesthesia methods, local anesthesia can reduce the incidence of postoperative venous thrombosis in trauma patients. General anesthesia not only increases the cost of anesthesia and the difficulty of intraoperative anesthesia management, but also causes pneumothorax due to the possibility of puncturing the pleura when the fractured end of the rib is mechanically ventilated. (2) The purpose of pressing below the injection point after completing the femoral nerve block is to make the local anesthetic spread upward to block the femoral nerve, lateral femoral cutaneous nerve and closed foraminal nerve at the same time, so it is also called “three-in-one” block. This can make the patient better tolerate the tourniquet. (3) Ropivacaine is a long-acting and safe new local anesthetic. Ropivacaine is the preferred local anesthetic for time-consuming procedures such as limb reimplantation and revascularization. With the help of a nerve stimulator ropivacaine is very close to the nerve to be blocked, prolonging the duration of action of ropivacaine.