Objective To explore the value of coronary CT angiography (CCTA) quantitative evaluation of myocardial bridge (MB) on the degree of mural coronary artery compression. Method The clinical data of patients with MB confirmed by CCTA in the hospital from August 2017 to March 2022 were retrospectively collected. The differences in general data, left anterior descending artery (LAD), transluminal attenuation gradient (TAG), TAG corrected value (TAGs), mural coronary artery (MCA)contrast opacification difference (MCA-COD) and MB depth and length were detected and compared among patients with different degrees of systolic compression (no compression group, mild compression group, significant compression group). Receiver operating characteristic (ROC) curve was used to analyze the efficiency of TAGs and MCA-COD on quantitatively evaluating MB significant systolic compression.Results From the aspects of general data, there were no statistical differences in gender, age, clinical symptoms, and high-risk factors among no compression group, mild compression group and significant compression group (P>0.05). Comparisons of CCTA parameters showed that the TAG and TAGs of patients with MB were successively reduced with the increase of degree of systolic compression while the MCA-COD was enhanced in turn, and the TAG, TAGs, and MCA-COD were significantly different among different groups (P<0.05), but the differences in MB depth and MB length among the different groups were not statistically significant (P>0.05). In terms of efficiency of TAG-related parameters in the quantitative evaluation of MB significant systolic compression, ROC curve results showed that the AUCs of TAGs and MCA-COD on quantitatively evaluating the significant systolic compression of MB were 0.844 and 0.815 (P<0.05), the AUC of the combination of the two was 0.935 (P<0.05), and the combined evaluation had higher efficiency. Conclusion CCTA can be used to quantitatively evaluate the degree of systolic compression in patients with MB, and the combined evaluation with TAGs and MCA-COD has high efficiency on the significant systolic compression of MB, which can provide more accurate guidance for clinical diagnosis