Abstract: Objective To analyze the risk factors for deep venous thrombosis (LDVT) in the lower limbs after lumbar interbody fusion (LIF) in patients with lumbar disc herniation (LDH) and to construct a prediction model. Methods A total of 256 LDH patients who underwent LIF at the Affiliated Hospital of Xuzhou Medical University from January 2022 to June 2023 (training set) and 109 LDH patients who underwent LIF at the same hospital from July 2023 to March 2024 (validation set) were included in the study. Based on the occurrence of LDVT after LIF, patients in the training set were divided into a non-LDVT group (n=215) and an LDVT group (n=41). The risk factors for LDVT formation in LDH patients after LIF were analyzed by Lasso-Logistic regression, and a nomogram was constructed by R software. The predictive performance of the model was evaluated by plotting receiver operating characteristic (ROC) curves and through the Hosmer-Lemeshow test. The clinical utility of the model was assessed by clinical decision curve analysis (DCA). Results In the training set, 41 patients developed LDVT after LIF, and 13 patients developed LDVT in the validation set, with an overall incidence rate of 14.79% (54/365). According to Lasso and multivariate logistic regression analysis in the training set, BMI ≥28 kg/m², postoperative D-dimer (D-D) ≥0.5 mg/L, abnormal coagulation parameters after surgery, and a postoperative bed rest duration >5 days were identified as independent risk factors for LDVT formation after LIF in LDH patients (P<0.05). ROC curve analysis revealed an area under the curve (AUC) of 0.887 (95%CI: 0.822-0.951) for the training set and 0.910 (95%CI: 0.841-0.979) for the validation set, demonstrating good discriminative ability. The Hosmer-Lemeshow test yielded values of χ²=8.152 (P=0.227) for the training set and χ²=2.779 (P=0.595) for the validation set, indicating high model consistency. Furthermore, DCA curves confirmed the model’s high clinical utility. Conclusions The nomogram based on BMI, postoperative D-D, the number of abnormal coagulation parameters, and postoperative bed rest duration can accurately predict the probability of LDVT formation in LDH patients after LIF.