Aim To compare and evaluate the clinical effect of Y-type coronary artery bypass and sequential bypass in the near and medium term. Methods From January 2014 to December 5,0 patients were randomly selected as the study subjects. The patients with Y-pattern anastomosis of great saphenous vein were recorded as the experimental group and the patients with sequential anastomosis as the control group. The preoperative general condition, intraoperative blood flow at each anastomotic port of vein bridge, left ventricular ejection fraction (LVEF), left ventricular end diastolic diameter (LVEDD), incidence of adverse cardiovascular events, CAG reexamination after admission due to similar symptoms were compared between the two groups. Results There was no significant difference in cardiac function between the two groups in the near future (3 months and 6 months after operation), and the incidence of adverse cardiovascular events was mainly in the middle postoperative period (2 and 3 years after operation) and later. There was no significant difference in body weight, age, cardiac function and instant blood flow measurement at each anastomotic site of venous bridge between the two groups before operation. Compared with the control group, the left ventricular ejection fraction (LVEF) of the observation group was significantly increased after 1,2 and 3 years of follow-up after operation(P＜0.05), while the incidence of adverse cardiovascular events, vascular bridge and anastomotic occlusion rate were significantly decreased (P＜0.05). Conclusion Compared with sequential coronary artery bypass grafting, Y-type saphenous vein bypass grafting can improve the postoperative cardiac function, reduce the incidence of postoperative complications and graft occlusion rate, which is of great significance to improve the mid-term survival rate of patients and worthy of clinical promotion.