Abstract： Objective To explore the influencing factors for incision infection in patients with lumbar instability and lumbar disc herniation after transforaminal lumbar interbody fusion.Methods A total of 1620 patients with lumbar instability and lumbar disc herniation who underwent transforaminal lumbar interbody fusion in our hospital from January 2017 to January 2023 were selected.They were divided into infection group(32 cases)and non-infection(1,588 cases)according to postoperative incision infection.Procalcitonin(PCT),C-reactive protein(CRP),erythrocyte sedimentation rate(ESR)and white blood cell count(WBC)were detected.Pathogens were identified by a drug sensitivity analyzer.Univariate and multivariate logistic regression analysis were performed to identify influencing factors for incision infection in patients with lumbar instability and lumbar disc herniation after transforaminal lumbar interbody fusion.Results Compared with those of non-infection group,PCT,CRP,ESR and WBC in the infection group were significantly higher(P＜0.05).In the infection group,the most popular pathogen was Staphylococcus aureus in 16 strains(50.00％),followed by Enterococcus faecalis in 8 strains(25.00％),Escherichia coli in 6 strains(18.75％)and Enterobacter cloacae in 2 strains(6.25％).Univariate analysis showed significant differences in the surgical segment,surgical time and incision length between groups(P＜0.05).Multivariate logistic regression analysis showed that multi-stage surgery,operation time＞2h and incision length ≥4cm were the main risk factors for postoperative incision infection in patients with lumbar instability and lumbar disc herniation.Conclusion Multi-segment surgery,operation time＞2h,incision length ≥4cm are the main risk factors for postoperative incision infection in patients with lumbar instability and lumbar disc herniation.By analyzing the above risk factors,the incidence of postoperative incision infection in patients with lumbar disc herniation can be reduced.