Abstract: [Objective] To identify the risk factors of proximal femoral anti-rotating intramedullary nail (PFNA) failure, establish a postoperative stability evaluation model based on the risk factors, and explore its predictive value. [Methods] : Clinical data of 207 patients with intertrochanteric fracture (intertrochanteric fracture of femur) in the First People's Hospital of Ningyang County from January 2019 to January 2022 were retrospectively analyzed. A total of 164 patients were included according to certain criteria. The demographic characteristics of the patients and other factors that might influence the outcome of surgery were recorded, and the outcome of the study was whether fixation failure occurred after surgery. The best prediction model was tested by step forward likelihood ratio test, and a stability scoring system was established according to the statistical results. The cut-off of score prediction failure was determined by receiver operating curve (ROC) with treatment outcome as state variable and score as statistical variable. [Results]① Lateral wall thickness, lateral wall fracture classification, Cal-TAD, medial cortical brace reduction, fracture reduction quality and spiral blade position were the risk factors for postoperative fixation failure of PFNA. ②ROC analysis results showed that: The cut-off of fixed failure prediction, area under curve (AUC), sensitivity and specificity were 6.5, 0.934, 94.74% and 73.02%. [Conclusion] The PFNA postoperative stability scoring system can comprehensively evaluate the postoperative stability of PFNA, and has important value in predicting the failure of postoperative fixation of PFNA.