Objective:To explore the analgesia effect of preemptive analgesia on patients after thoracoscopic lobectomy under spontaneous breathing.Methods:116 patients who received thoracoscopic lobectomy were included as the study subjects.According to the intervention methods,58 patients who received thoracic paravertebral nerve block under spontaneous breathing were randomly col-lected as control group,and 58 patients who adopted preemptive analgesia combined with thoracic paravertebral nerve block under spon-taneous breathing were included in study group.The intraoperative vital signs[heart rate(HR),mean arterial pressure(MAP),blood oxygen saturation(SPO2)],analgesia and sedation effects[visual analogue scale(VAS)score,Ramsay sedation score],pain factors[prostaglandin E2(PGE2),substance P(SP),dopamine(DA)]and inflammatory factors[tumor necrosis factor-α(TNF-α),inter-leukin-6(IL-6),C-reactive protein(CRP)]after surgery and incidence rates of adverse reactions were compared between the two groups.Results:There were no statistical differences in HR,MAP,and SPO2 before anesthesia between groups(P＞0.05).After anes-thesia,HR and MAP in study group were lower than those in control group(P＜0.05)while SPO2 was higher than that in control group(P＜0.05).After surgery,the VAS score,Ramsay score,and levels of PGE2,SP,DA,TNF-α,IL-6,and CRP in study group were lower than those in control group(P＜0.05).There were no statistical differences in the incidence rates of adverse reactions between groups(P＞0.05).Conclusion:For patients undergoing thoracoscopic lobectomy,the application of nalbuphine hydrochloride for preemptive analgesia can enhance the analgesia effect,stabilize hemodynamic indicators,and alleviate postoperative pain and inflammatory reac-tions.