Objective To explore the clinical value of computed tomography angiography (CTA) in the diagnosis of coronary artery stenosis. Methods A total of 82 patients with suspected coronary heart disease who were admitted to the hospital from October 2016 to October 2017 were randomly selected as the subjects. They were examined by CTA and digital subtraction angiography (DSA), and the results were compared with results of DSA as the golden standard. Results There were 79 cases positive and 3 cases negative detected by DSA, while there were 75 cases of coronary arteries positive and 7 cases negative detected by CTA. The sensitivity, specificity, accuracy and Kappa value were 96.10% (74/77), 80.00% (4/5), 95.12% (78/82) and 0.64, respectively, without significant difference between CTA and DSA in detecting the degree of coronary artery stenosis (P>0.05). The sensitivity, specificity, accuracy and Kappa value of CTA for left main stem were 95.24% (40/42), 100.00% (40/40), 97.56% (80/82) and 0.95, respectively, those for left anterior descending branch were 95.00% (57/60), 100.00% (22/22), 96.34% (79/82) and 0.91, for left circumflex branch were 92.16% (47/51), 96.77% (30/31), 93.90% (77/82) and 0.87, and for right coronary artery were 95.24% (40/42), 100.00% (40/40), 97.56% (80/82) and 0.95, respectively. Conclusion CTA can clearly display coronary artery lesions, with high accuracy, sensitivity and specificity. It can help diagnosis and screening of coronary artery stenosis.