Objective To explore the characteristics of blood flow in orthopedic patients with increased risk of intraoperative deep venous thrombosis(DVT) and analyze relevant influencing factors, so as to provide a reference for nursing intervention in the operating room. Methods A total of 151 patients who underwent elective orthopedic surgery were selected as the study subjects. Doppler ultrasound diagnostic instrument was used to observe the blood flow changes in lower extremities during the operation. The basic data of patients, operation-related data and preoperative laboratory examination indexes also were collected. Blood samples were collected from the patients within 24 hours after the operation for a D-dimer coagulation test. Results The results of the D-dimer test showed that there were 70 patients with a high risk of DVT (46.36%) and 81 patients with a low risk (53.64%). The mean blood flow velocity and vascular diameter of the patient′s lower limbs at high risk for DVT were significantly lower than those of patients at low risk after surgery（P＜0.05 for both）. Multivariate analysis showed that operation time＞120 min, PT＞13.1 s, hypothermia and intraoperative blood loss＞100 mL were independent risk factors for increased risk of intraoperative DVT（all P＜0.05）. Conclusion Patients undergoing orthopedic surgery are at high risk of intraoperative DVT with significant hemodynamic changes. The nursing staff in the operating room need to carry out targeted surgical efficiency management, intraoperative hypothermia monitoring and prevention, maintain intraoperative blood volume stability, and effectively reduce the risk of DVT during the surgical process.