[Objective] To introduce the method and clinical effect of traction device reduction and dynamic cross nail internal fixation for young and middle-aged femoral neck fractures under C-arm three-dimensional imaging. [Methods] Twenty-one young and middle-aged patients with femoral neck fractures were treated with C-arm three-dimensional imaging with traction device reduction and dynamic cross screw (FNS) internal fixation. The affected side is elevated by 40 degrees, in an oblique lateral recumbent position, with osteotomy traction on the distal femoral condyle of the fracture, and a fracture retractor is installed. The affected limb is rotated outward, vertically opposing the traction of the fracture end, and the affected limb is adducted and rotated inward to reduce the fracture. C-arm three-dimensional imaging shows fracture reduction. A longitudinal 3cm incision is made from the subtrochanteric region of the femur to the distal end. The skin, tensor fascia lata, and lateral femoral muscles are cut. The proximal lateral wall of the femur is stripped and exposed, and a positioning guide is placed. The guide needle is drilled along the positioning guide into the femoral neck 5 mm below the cartilage. C-arm three-dimensional imaging judges the position of the guide needle in the center of the femoral neck. After the position is correct, a hollow drill is drilled along the guide needle. Install the outer side plate of the power rod onto the collimator, rotate and tap to place the power rod along the drill hole, and the outer plate is attached to the outside of the femur and parallel to the central axis of the femoral shaft. Drill holes for the aiming guide, screw in the locking screw holes and anti rotation screws at the distal end of the outer panel, and close the incision. The operation time, blood loss, fluoroscopy time, fracture reduction quality, fracture healing time, and Harris score of hip joint function were observed. [results] In 21 patients, the operative time (54.2 ± 11.3 min), intraoperative bleeding volume (197.5 ± 18.3 ml), fluoroscopy time (65.1 ± 3.2 S), fracture reduction quality (Garden index), grade I in 16 cases, grade II in 5 cases, fracture healing time (3.5 ± 1.5 months), and hip joint function Harris score (84.5 ± 4.2 points) were evaluated .[Conclusion] C-arm three-dimensional imaging traction device reduction and dynamic cross screw (FNS) internal fixation for the treatment of femoral neck fractures in young and middle-aged adults has a short surgical time, can reduce the number of intraoperative imaging examinations, improve the accuracy of reduction and surgery, stable fracture fixation, rapid healing, and satisfactory recovery of hip joint function.