CABG technology is recognized as the preferred treatment, and its major adverse cardiac and cerebral event(MACCE) incidence and mortality are lower than percutaneous coronary intervention(PCI). However, the traditional CABG procedure requires sternal incision, large trauma and long recovery period after surgery. How to reduce trauma and treat multiple complex coronary lesions under minimally invasive conditions has become a hot spot. MIDCAB surgery can complete the coronary anastomosis only by a 6-8 cm incision in the left chest. It has been more than ten years since the first literature report in the world, however, due to the technical bottleneck, a unified and standardized surgical procedure has not yet been formed. Some centers are still in the exploratory stage, and internationally Large-scale studies of clinical outcomes (mostly less than 150 cases) have not been reported. Assessing the minimally invasive procedure's safety and effectiveness has become an urgent problem to be solved. At present, our center has completed nearly 200 cases of small incision multi-coronary coronary artery bypass graft surgery. The investigators evaluate the patency of the graft by the postoperative of angiography, the patency of grafts is more than 95%, and there is no statistical difference with conventional OPCABG. On the other hand, focus on the postoperative complications, there was no significant difference in the incidence of MACCE and revascularization between the MIDCAB group and conventional surgery during hospitalization. The investigators assume that the early results of this procedure are safe and effective. MIDCAB has a congenital advantage because of its' reduction of the trauma of the thoracotomy and the aesthetics of the incision. Therefore, if a larger sample size study and mid-term follow-up results are obtained, and the conclusion prove that the safety of the small incision surgery and the patency of the grafts are not inferior to conventional surgery. The investigators can consider that minimal invasive coronary surgery(MICS) is a technique worth trying to promote. Through this prospective cohort study, the investigators evaluated the safety of MICS through mid-term follow-up results and asses the efficiency by the results of grafts patency (angiography or CT within 30 days after surgery) and medical outcomes study-short from scores(SF-36), establish the surgical standard and perioperative management method.