Objective：To evaluate the clinical effect of 3D reconstruction images of coronary CT angiography in preoperative planning of off-pump coronary artery bypass grafting.Methods：The clinical data of 158 patients who underwent coronary artery bypass grafting from January 2021 to March 2023 in the Department of Cardiac Macrovascular Surgery of the First Affiliated Hospital of Nanjing Medical University were retrospectively analyzed. Among them, 113 patients underwent conventional coronary artery bypass grafting guided by coronary angiography (conventional group) and 45 patients underwent coronary artery bypass grafting guided by coronary angiography and Three-dimensional reconstruction of coronary artery CT angiography (3D group). The outcome measures included operation time, Intraoperative blood loss,ventilator use time, postoperative monitoring time and hospital stay, postoperative atrial fibrillation, acute kidney injury and other complications, and 1 year postoperative cardiac ultrasound and coronary CT angiography follow-up results.Results：There was no significant difference between the two groups in the time of ventilator use, the time of postoperative monitoring, the time of hospital stay, and the results of coronary CT angiography and cardiac ultrasound follow-up 1 year after surgery (p>0.05) However, the operation time of the 3D group (250.69±41.42) and the conventional group (270.97±57.19), the difference between the two groups was statistically significant (p<0.05), and the amount of blood loss during the 3D operation was less than that of the conventional group (p<0.05)..Conclusion：Compared with conventional CAG guided off-pump coronary artery bypass grafting, the addition of coronary CT angiography can shorten the operation time, reduce the amount of intraoperative blood loss, and obtain better surgical results.