Abstract: Objective To study the effect of thrombolytic therapy on ACS in patients with acute myocardial infarction and its effect on cardiac function, myocardial necrosis and inflammatory index. Methods Seventy patients with acute myocardial infarction from December 2017 to June 2018 in our hospital emergency department admissions ST elevation cases, thrombolytic therapy for patients, and according to the time of thrombolysis were divided into thrombolysis group 0-1 h, 1-3 h, 3-6 h thrombolysis group, thrombolysis group. The cardiac function, myocardial necrosis and inflammatory index were measured and compared. Results E peak, E/A ratio, LVEF, LVEDD were higher in the 0-1 h thrombolysis group than in the thrombolysis group and the thrombolytic group of 3-6 h in the group from 1 to 3 h, the difference was statistically significant (P < 0.05), and there was a negative correlation between cardiac function and thrombolysis time.The c Tn T, LDH, CK-MB levels of 0 to 1 h thrombolysis group were lower than those of thrombolysis group and thrombolysis group from 1 to 3 h in the group from 3 to 6 h, the difference was statistically significant (P < 0.01). There were positively correlated between the indexes of myocardial cell necrosis and thrombolysis time. The inflammatory factors CRP, TNF, IL-1 levels in 0-1 h thrombolysis group were lower than those in the group of thrombolytic therapy from 1 to 3 h and from 3 to 6 h, the difference was statistically significant (P < 0.01). Inflammatory index was positively correlated with thrombolysis time. Conclusion The shorter the time of thrombolytic therapy, the better the cardiac function of patients after thrombolysis. The less necrosis of myocardial cells, the lower the level of inflammatory response.