〔Abstract〕 Objective To explore the effect of light specific gravity combined spinal-epidural anesthesia on the stress response of elderly patients undergoing orthopedic surgery on the lower extremities. Methods A total of 98 elderly patients undergoing orthopedic surgery on lower limbs were selected from Jinan District Hospital of Fuzhou from March 2019 to August 2020. They wererandomly divided into group A (tracheal intubation general anesthesia) and group B (light specific gravity arachnoid membrane). Inferior cavity block combined with epidural anesthesia), 49 cases in each case. Observe the blood pressure and stress response of the two groups of patients before anesthesia (T0), during anesthesia (T1), 30 minutes after anesthesia (T2), and after extubation (T3). Results The systolic blood pressure (SBP) and diastolic blood pressure (DBP) of the two groups were lower than T0 at T1 and T2, and the SBP and DBP of the two groups were lower than T1 at T2. The differences were statistically significant. (P < 0.05), and compared with group B in SBP and DBP at T1 and T2, the difference was statistically significant (P < 0.05); the adrenocorticotropic hormone (ACTH) and cortisol ( Cor) and β-endorphin (β-EP) are higher than T0 at T1 and T2, and ACTH, Cor and β-EP of the two groups are lower than T1 at T2, the differences are statistically significant (P < 0.05). In addition, the ACTH, Cor and β-EP of group A patients were compared with group B at T1 and T2, and the differences were statistically significant (P < 0.05). Conclusion The use of light specific gravity subarachnoid combined with epidural anesthesia in elderly patients undergoing orthopedic surgery for lower extremities can significantly reduce the stress response during the operation, with less impact on the circulation of patients, and better safety.