Objective To explore the value of multi-slice spiral CT (MSCT) in diagnosing coronary heart disease (CHD) and predicting in-stent restenosis after percutaneous coronary intervention (PCI). Methods 94 patients with CHD admitted to the hospital from July 2015 to January 2017 were selected as the study subjects. All patients underwent MSCT coronary artery examination and underwent coronary angiography (CAG) within 2 weeks. 38 cases treated with PCI were examined with MSCT and CAG at 6 months after stent implantation. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy rate of MSCT in diagnosing CHD and in-stent restenosis after PCI were calculated with the diagnostic results of CAG as the golden standard. Results The sensitivity, specificity, positive predictive value, negative predictive value and accuracy rate of MSCT in evaluating coronary artery stenosis were 86.30%, 97.23%, 90.00%, 96.09% and 94.78% respectively, while those in evaluating in-stent restenosis after PCI were 80.00%, 94.73%, 88.89%, 90.00% and 89.65% respectively. The consistency of MSCT and CAG was good in the diagnosis of coronary artery stenosis and in-stent restenosis after PCI. Conclusion MSCT can well display coronary artery stenosis, and it can also be used for the diagnosis of in-stent restenosis after PCI. It can be used for screening CHD and routine examination after PCI.