Abstract: Objective To investigate the effect of Jintiange Capsules on postoperative pain in patients undergoing internal fixation for thoracolumbar fractures, and to explore its potential mechanism through the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling pathway. Methods A total of 150 patients who underwent internal fixation for thoracolumbar fractures in Handan First Hospital from January 2020 to December 2024 were enrolled and randomly assigned to a control group or a study group using the random number table. The control group received conventional treatment, while the study group was administered Jintiange Capsules in addition to the conventional treatment. The two groups were compared in terms of visual analogue scale (VAS) scores at 1, 7 and 14 days postoperatively, postoperative complications, levels of pain factors, cAMP and PKA at 1 and 14 days postoperatively, and changes in the Oswestry Disability Index (ODI) at 1 day, 14 days and 3 months postoperatively. Results At 7 days and 14 days postoperatively, the VAS scores in both groups were lower than those at 1 day postoperatively (P ＜ 0.05), with the study group demonstrating lower scores than the control group (P ＜ 0.05). The total incidence of postoperative complications in the study group was lower than that in the control group (P ＜ 0.05). At 14 days postoperatively, the serum levels of prostaglandin E2 (PGE2), neuropeptide Y (NPY), substance P (SP), cAMP and PKA in both groups were lower than those at 1 day postoperatively (P ＜ 0.05); the serum levels of PGE2, NPY, SP, cAMP and PKA in the study group at 14 days postoperatively were all lower than those in the control group (P ＜ 0.05). At 14 days and 3 months postoperatively, the ODI scores in both groups were lower than those at 1 day postoperatively (P ＜ 0.05), with the study group demonstrating lower scores than the control group (P ＜ 0.05). Conclusion Jintiange Capsules can significantly relieve postoperative pain following internal fixation for thoracolumbar fractures. The mechanism may be related to down-regulating the expression of the cAMP/PKA signaling pathway. Additionally, Jintiange Capsules can reduce postoperative complications and improve thoracolumbar function.