Objective To analyze the diagnostic value of dynamic electrocardiogram (DCG) combined with multi-slice spiral CT (MSCT) for silent myocardial ischemia (SMI). Methods A total of 120 patients with suspected coronary heart disease and treated in our hospital from October 2016 to October 2018 were selected. All were given DCG, SMI and myocardial perfusion imaging (MPI) examination. The image features were analyzed. Taking MPI as the gold standard (80 patients with SMI in the SMI group, 40 patients with symptomatic myocardial ischemia in the symptomatic group), the diagnostic value of DCG combined with MSCT for SMI was evaluated. Results In the DCG examination, the array time change of ST segment in the SMI group were higher than those in the symptomatic group, while the ST segment decline range, the ST segment decline duration and the variability of myocardial ischemic threshold were lower than the symptomatic group (P<0.05). The onset performance of myocardial ischemic in the two groups was highest at 6:00 to 12:00h and lowest at 0:00 to 6:00. There was no significant difference between the two groups (P>0.05). MSCT coronary angiography showed that the degree of coronary artery stenosis, calcification plaque and incidence of myocardial bridge in SMI group were higher than those in the symptomatic group (P<0.05). There was no significant difference between the two groups in soft plaque, rate of opening abnormality combined with stenosis (P>0.05). The diagnosis sensitivity, specificity, accuracy and Kappa values of SMI by DCG combined with MSCT were 87.50%, 92.50%, 89.17%, and 0.766, respectively, which were all higher than those by DCG and MSCT alone (P<0.05). Conclusion DCG combined with MSCT has high diagnostic value for SMI. And MSCT coronary artery imaging helps the detection of abnormal changes of SMI coronary artery.