Objective To study the evaluated value of real-time three-dimensional echocardiography (RT-3DE) combined with 640-slice spiral CT (640-MSCT) in left ventricular systolic function in patients with coronary heart disease (CHD). Methods Sixty patients with CHD admitted to the hospital from January 2017 to January 2018 were enrolled in CHD group. Another 60 healthy people who underwent healthy physical examination at the same time period were included in healthy control group. The results of RT-3DE and 640-MSCT were compared between the two groups. The results of RT-34DE and 640-MSCT examination were compared among patients with CHD. The correlation between the two examinations in evaluating cardiac function in patients with CHD was analyzed. Results RT-3DE and 640-MSCT examinations showed that the measurement levels of EDV, ESV and SV in CHD patients were significantly higher than those in healthy control group, and the result of EF was significantly lower than that in healthy control group (P<0.05). The detection values of EDV, ESV and SV by 640-MSCT for patients with CHD were higher than those by RT-3DE while the detection value of EF was lower than that by RT-3DE. However, there were no significant differences between the two examination methods in the examination results of cardiac function indexes (P>0.05). RT-3DE and 640-MSCT had good correlations between cardiac function indexes EDV, ESV, SV and EF in patients with CHD (r=0.871, 0.801, 0.715, 0.657, all P<0.05). Conclusion Both RT-3DE and 640-MSCT can accurately evaluate the cardiac function of patients with CHD. The two examination methods have strong correlations in the evaluation of cardiac function indexes, but both have their advantages and disadvantages, and appropriate examination methods should be chosen by combination of specific conditions in clinical application, if necessary, the two examination methods can be combined to improve clinical imaging diagnosis.