Objective To evaluate the diagnostic value of dual-source CT coronary angiography (DSCTCA) in the left anterior descending (LAD) coronary stenosis classification. Methods A total of 98 patients suspected as CAD in our hospital were selected for the study and were given selective coronary angiography (CAG) and DSCTCA. The CAG results were used as the gold standard to evaluate the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of DSCTCA in the diagnosis of LAD stenosis. The Kappa test was used to analyze the consistency of CAG and DSCTA examination results, and the coincidence rate of DSCTCA for different LAD stenosis was analyzed. Results A total of 1256 coronary vessels were available for analysis in 98 patients, and there were 282 segments of left anterior descending (LAD), and 165 segments (58.51%) were for LAD stenosis by CAG and 158 segments (56.03%) by DSCTA, and there was no significant difference between the two diagnostic methods (P>0.05). The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of DSCTCA for LAD stenosis were 95.15%, 99.15%, 96.81%, 99.37% and 93.55% respectively, and the consistency with CAG diagnosis was high (Kappa value=0.935). The coincidence rate of DSCTA for different LAD stenosis was 90.78%. Conclusion DSCTCA has high sensitivity, specificity, positive predictive value and negative predictive value for LAD stenosis. And it is of high diagnostic value for evaluating LAD stenosis classification.