Background: This study sought to compare and evaluate the clinical efficacy and safety of Y-type coronary artery bypass grafting (CABG) and sequential CABG. However, the prognosis and complication rate of the two treatments are different. Therefore, we need to systematically compare the efficacy and safety of the two surgical schemes.Methods: A total of 112 patients who underwent Y-type CABG and 113 patients who underwent sequential CABG were selected from January 2020 to December 2020. The patients undergoing Y-type CABG of the great saphenous vein (SV) were classified as the experimental group, and those undergoing sequential anastomosis were classified as the control group. The intraoperative blood flow at each anastomotic site of the venous sequential CABG, left ventricular ejection fraction (LVEF), and left ventricular diastolic diameter (LVEDD) at the end of 3 months, 6 months, and 1 year after surgery, the incidence rate of major adverse cardiovascular events, and coronary angiography (CAG) after readmissions due to similar symptoms were compared between the 2 groups. The bridging vascular blockage rate was also determined.Results: There was no significant difference in cardiac function between the 2 groups in the short term, and the incidence of major adverse cardiovascular events in the 2 groups mainly occurred in the middlepostoperative period (1 year after surgery) or later. There was no statistical difference in the intraoperative real-time blood flow measurements at each anastomosis of the venous bridge between the 2 groups.Compared to the control group, the LVEF of the experimental group was significantly increased at the 1-year follow-up point (51.6±5.1 vs. 67.6±5.6, P=0.001). During the operation of Y-type coronary artery bypass grafting, the incidence of major adverse cardiovascular events, vascular bridge, and anastomotic blockage were significantly decreased (16 vs. 39, P=0.023).Conclusions: Large SV Y-type CABG can improve postoperative left heart function and reduce the incidence of postoperative adverse events, which may be of great significance for improving the postoperative mid-term survival rate of patients.