Abstract: Objective: To investigate the application value of Gemstone spectral CT in coronary stents. Methods: CTA data of 45 patients with coronary stent implantation were collected, and the actual diameter of stent lumen was measured, and the difference of CT value between the stent lumen and adjacent vascular cavity was compared. Results: a total of 60 stents were found, which showed clear and no stenosis. 1, when the actual stent lumen diameter ≥ 2 mm, the stent lumen CT value measurement with good stability, the stent lumen CT value had no significant difference with the adjacent vascular cavity CT. 2, stent lumen diameter < 2 mm, the measurement of CT value of stent lumen is not stable and inaccurate, MPR images can still partially observe the stent lumen. Conclusion: Gemstone spectral CT has a higher diagnostic value for stents with a diameter ≥ 2 mm, and a definite diagnostic value for stent lumen diameter < 2 mm.