【ABSTRACT】Objective: To investigate the value of three-dimensional speckle tracking imaging(3D-STI) in the diagnosis of severe multi-vessel coronary artery stenosis of non-myocardial infarction in resting state. Methods: 100 patients with suspected coronary heart disease who underwent coronary angiography which was selected as the research objects in our hospital from January 2018 to December 2018. Patients were divided into severe multi-vessel stenosis group (40 cases), severe single-vessel stenosis group (30 cases) and control group (30 cases) according to the results of coronary angiography. All patients were detected by three-dimensional echocardiography, and 3D-STI technology was used to measure the global longitudinal strain (3D GLS), global circumferential strain (3D GCS), global area strain (3D GAS) and global radial strain (3D GRS) of the left ventricle. ROC curve was used to analyze the value of 3D-STI in the diagnosis of severe multi-vessel coronary artery stenosis. Results：The 3D GLS, 3D GCS, 3D GAS, 3D GRS of severe multi-vessel stenosis group and severe single-vessel stenosis group was significantly lower than that of control group (P<0.05). The 3D GLS, 3D GAS of severe multi-vessel stenosis group was significantly lower than that of severe single-vessel stenosis group(P<0.05). The AUC of 3D GLS was 0.78, and the sensitivity was 85.1% when the cutoff value was -12%. The AUC of 3D GAS was 0.77, and the specificity was 80.2% when the cutoff value was -21%. When 3D GLS is used in parallel with any of the indicators of 3D GCS, 3D GAS and 3D GRS, the sensitivity of diagnosis of severe multi-vessel coronary artery stenosis was higher than that of single indicator. Conclusion：3D-STI had certain diagnostic value for severe multi-vessel coronary artery stenosis of non-myocardial infarction in resting state, especially 3D GLS and 3D GAS could be used as more effective diagnostic indicators for severe multi-vessel coronary artery stenosis.