Abstract :[Objective]To analyze the risk factors of Fracture-related infection (FRI) in the lower limbs, in order to better prevent FRI in the clinic. [Methods]The data of 5982 patients who underwent fracture fixation treatment of the lower limbs admitted to the Second Hospital of Tangshan City from January 2018 to January 2022 were collected, and 83 patients who developed FRI of the lower limbs were included in the infected group (case group), and according to the method of matching fracture site, fracture operation style (closed or incised reduction and internal fixation), gender, and age (difference of ±3) among groups, we chose the patients who did not 166 patients who developed FRI were included in the no-infection group (control group), and risk factors for FRI after lower extremity fracture fixation were analyzed using univariate analysis and binary multifactorial logistic regression. [Results]Univariate analysis showed that the differences in open injury, operative time, intraoperative bleeding, history of smoking, history of diabetes mellitus, body mass index (BMI), ASA classification, and preoperative ALB were statistically significant (P < 0.05), whereas there was no statistically significant difference in the history of hypertension, history of alcohol consumption, mechanism of injury, hospitalization time, injury-to-operation time, fracture technique, and lateralization Significance. Multifactorial logistic regression analysis showed that after excluding the effects of fracture site, fracture procedure, gender, and age, history of smoking, prolonged operative time, high BMI, high ASA classification, and open injury were added as risk factors for FRI of the lower extremities, and high ALB was a protective factor for the occurrence of FRI of the lower extremities.[Conclusion]A history of smoking, prolonged surgical time, high BMI, high ASA classification, and open injuries have a higher risk of lower extremity FRI, and clinical measures should be taken to prevent them.