Objective To explore the correlation between CT angiography (CTA) parameters and the severity of coronary heart disease (CHD), and to further analyze the prognostic value of CTA in patients with CHD. Methods 72 patients with coronary heart disease admitted to our hospital from February 2022 to March 2024 were included in the study group. In addition, 72 healthy subjects who underwent physical examination in our hospital during the same period were included in the control group. CTA parameters were detected and compared between the two groups at admission. According to the Gensini score, patients in the study group were divided into mild group < 25 points (32 cases), moderate group 25-49 points (25 cases), and severe group ≥50 points (15 cases). The correlation between CTA parameters and Gensini scores was analyzed. According to the occurrence of adverse cardiovascular events 6 months after treatment, the study group could be divided into a good prognosis group (13 cases) and a poor prognosis group (59 cases). CTA parameters of the two groups were detected and compared, and the predictive value was analyzed by receiver operating characteristic (ROC) curve. Results The volume of calcified plaque, the volume of non-calcified plaque, the load of calcified plaque, the load of non-calcified plaque, the degree of vascular stenosis and the reconstruction index of the study group were significantly higher than those of the control group (P < 0.05). CTA parameters of patients with different disease degrees were compared: severe > moderate > mild (P < 0.05). The volume of calcified plaque, the volume of non-calcified plaque, the load of calcified plaque, the load of non-calcified plaque, the degree of vascular stenosis and the reconstruction index were positively correlated with Gensini score (P < 0.05). The CTA parameters of good prognosis were significantly lower than those of poor prognosis (P < 0.05). The AUC of CTA parameter predicting poor prognosis in CHD patients was 0.860 (95%CI: 0.843~0.878), the best prediction sensitivity was 92.31%, and the specificity was 79.66%. Conclusion CTA parameters are closely related to the severity of coronary heart disease. Clinical observation of CTA parameters can effectively evaluate the prognosis.