Objective To explore the efficacy of femoral neck system (FNS) in the treatment of Pauwels Ⅱ-Ⅲ femoral neck fractures in young and middle-aged patients. Methods The clinical data of 13 young and middle-aged patients with femoral neck fractures undergoing FNS treatment were retrospectively analyzed. There were 8 males and 5 females, with an age of (50.9±14.1) years. The Pauwels of fractures were type Ⅱ in 4 cases and type Ⅲ in 9 cases. Preoperative and postoperative Harris hip score, Barthel index score and visual analogue scale (VAS) score were compared. Results The operative time of the 13 patients was (52.08±11.54) min, intraoperative blood loss was (68.8±20.4) mL, intraoperative fluoroscopy was (12.8±2.2) times, and hospital stay was (5.8±1.7) d. The Garden alignment index was used to evaluate the quality of fracture reduction. There were 8 cases of grade Ⅰ and 5 cases of grade Ⅱ. The fracture healing time was (4.0±0.7) weeks. Two cases (15.4%) were complicated with femoral neck shortening (1 mild, 1 moderate), and no concurrent lower limb venous thrombosis was found. The postoperative partial weight-bearing time was (4.1±1.0) weeks, and complete weight-bearing time was (7.2±0.9) weeks. The Harris hip score was 89.46±4.35, Barthel index score was 79.92±22.17, and VAS score was 0.69±0.75 at 6 months after surgery; at 12 months after surgery, the above indicators were 90.77±3.37, 91.31±3.82, and 0.62±0.65, respectively, which were significantly improved compared with those before operation (18.08±6.70, 23.38±7.07, and 8.08±1.32) (all P<0.01). Conclusion FNS is effective in the treatment of young and middle-aged patients with PauwelsⅡ-Ⅲ femoral neck fractures. It has the advantages of less trauma, good healing of fracture block and fewer complications.