Objective：To observe the effect of dexmedetomidine combined with lidocaine pretreatment on perioperative cardiac events in patients undergoing thoracoscopic lung cancer surgery. Methods：Eighty patients undergoing thoracoscopic lung cancer surgery were randomly divided into two groups：the dexmedetomidine combined with lidocaine pretreatment group（group DL，n=40） and the control group（group C，n=40）. 1 μg/（kg·h） dexmedetomidine and 2 mg/（kg·h） lidocaine in group DL，and saline in group C was administered during anesthesia induction and last for 30 minutes. The serum level of hs-cTnT and NT-proBNP was measured before operation，as well as 24 h，48 h and 72 h after operation，and the incidence of cardiac events during operation and within 30 days after operation was recorded. Results：There was no significant difference in levels of hs-cTnT and NT-proBNP between the two groups before operation（P>0.05），but the levels of hs-cTnT at 48 h and 72 h and the levels of NT-proBNP at 24 h，48 h and 72 h after operation were significantly higher than those before operation. The levels of hs-cTnT at 48 h and the levels of NT-proBNP at 24 h，48 h and 72 h after operation in group DL were significantly lower than those in group C（P<0.05）. There were no myocardial infarc－tion and cardiac arrest event after operation in both groups. The incidence of intraoperative atrial premature，asymptomatic myocardial ischemia and arrhythmia in group DL was significantly lower than those in group C（P<0.05）. Conclusion：Pretreatment of dexmedeto－midine combined with lidocaine can reduce the levels of my－ocardial injury markers and the incidence of cardiac events in patients undergoing thoracic lung cancer surgery.