Objective To compare the effectiveness of biplanar vertical fixation and inverted triangle fixation with hollow screw for Pauwels type Ⅲ femoral neck fracture in young and middle-aged patients. Methods The clinical data of 55 young and middle-aged patients with Pauwels type Ⅲ femoral neck fracture between June 2021 and December 2022 was retrospectively analyzed. All patients were treated with closed reduction and internal fixation with hollow screws, 25 cases were treated with biplanar vertical fixation (study group), 30 cases with inverted triangle fixation (control group). There was no significant difference in gender, age, affected side, cause of injury, underlying diseases, and time from injury to operation between the two groups (P>0.05). The operation time, intraoperative blood loss, fluoroscopy times, guide needle puncture times, starting time of weight bearing, time of full weight bearing, time of fracture healing, and complications were recorded and compared between the two groups. The hip joint function was evaluated by Harris score at 1 day, 6 months, 12 months after operation, and at last follow-up, and the pain relief was evaluated by visual analogue scale (VAS) score. The femoral neck shortening was measured on the X-ray film at last follow-up. Results All patients were followed up 12-31 months (mean, 22.0 months), and there was no significant difference in follow-up time between the two groups (P>0.05). The operation time, intraoperative blood loss, and fluoroscopy times in the study group were higher than those in the control group, but the difference was not significant (P>0.05). The guide needle puncture times in the study group was more than that in the control group, and the time of starting weight bearing and the time of full weight bearing in the study group were shorter than those in the control group, the differences were significant (P<0.05). Bony healing was achieved in both groups, and there was no significant difference in fracture healing time between the two groups (P>0.05). No osteonecrosis of the femoral head and incision-related complication was found in the two groups during follow-up, and the femoral neck shortening length in the study group was significantly shorter than that in the control group at last follow-up (P<0.05). There was no significant difference in Harris score between the two groups at 1 day after operation (P>0.05), and the Harris score of the study group was significantly better than that of the control group at other time points (P<0.05); there was no significant difference in VAS score between the two groups at each time point after operation (P>0.05). Conclusion Compared with the inverted triangle fixation, the treatment of Pauwels type Ⅲ femoral neck fracture with biplanar vertical fixation can effectively reduce femoral neck shortening without affecting fracture healing, and improve hip joint function in early stage.