Objective: To investigate the correlation between intestinal flora imbalance and depression with coronary heart disease, and analyze the predictive value of intestinal flora imbalance on the prognosis of depression with coronary heart disease. Methods: 80 patients with depression admitted to our hospital from June 2021 to May 2022 were selected as the research objects. 49 patients with simple depression were divided into depression group, 31 patients with coronary heart disease were divided into depression and coronary heart disease group, and 40 healthy people who came to our hospital for physical examination at the same time were selected as the control group to compare the intestinal flora of the three groups, Spearman correlation analysis was used to analyze the correlation between intestinal flora imbalance and depression with coronary heart disease. Subsequently, 31 patients with depression and coronary heart disease were followed up, and they were divided into good prognosis group (n=21) and poor prognosis group (n=10). The clinical general conditions and intestinal flora of the two groups were compared, and the prognostic value of intestinal flora for depression and coronary heart disease was analyzed by logistic regression analysis. Results: There was no difference in Bacteroides among the three groups (P>0.05). There was a difference in the comparison of Enterobacteriaceae, Enterococcus. Bifidobacterium, Lactobacillus and B/E values. The levels of Enterobacteriaceae and Enterococcus in the depression with coronary heart disease group were higher than those in the depression group and the control group, and the values of Bifidobacterium, Lactobacillus and B/E were lower than those in the depression group and the control group (P<0.05); Spearman correlation analysis showed that there was no significant correlation between the level of Bacteroides in intestinal dysbacteriosis and depression with coronary heart disease (P>0.05). The levels of Enterobacteriaceae and Enterobacteriaceae in intestinal dysbacteriosis were positively correlated with depression with coronary heart disease, and negatively correlated with the logarithmic ratio (B/E) of the number of Bifidobacterium, Lactobacillus, Bifidobacteriaceae and Enterobacteriaceae (P<0.05); There was no difference in the scores of hs cTnT, NT proBNP, NT proBNP, PHQ-9 and Bacteroides between the group with good prognosis and the group with poor prognosis, age, BMI, concomitant basic diseases (P>0.05), but there was difference in hs CRP, Enterobacteriaceae. Enterococcus, Bifidobacterium, Lactobacillus and B/E values (P<0.05): Logistic regression analysis showed that only hs CRP and B/E value dysbacteriosis had independent predictive value for the prognosis of depression with coronary heart disease (P<0.05). Conclusion: The proportion of intestinal flora in patients with depression combined with coronary heart disease is more imbalance than that in patients with single depression and healthy people, and the imbalance of intestinal flora is significantly related to depression combined with coronary heart disease. The application of B/E value can predict the prognosis of patients with depression combined with coronary heart disease. [ABSTRACT FROM AUTHOR]