Objective The purpose of this study was to compare and evaluate the diet quality of tuberculosis patients and healthy adults by using the China Healthy Diet Index (CHDI) and to provide guidance for the diet of tuberculosis patients in the future. Methods A case–control study of 1241 patients and 1241 healthy individuals matchedfor sex and age. The CHDI was used to score the overall diet quality of patients in the casegroup and the control group. Results The CHDI score of tuberculosis patients was 61.61 and that of healthy controls was 63.97. After adjustment for confounders, participants with >80 on CHDI were 73.5% less likely to develop tuberculosis than participants with <51 (OR: 0.265, 95% CI: 0.086, 0.813, p < 0.05). In the original model, the CHDI scores in the highest range were inversely associated with tuberculosis risk compared with the lowest range (OR: 0.687, 95% CI: 0.420,1.122, p < 0.001). After adjusting for confounders, the CHDI score was significantly associated with a reduced risk of tuberculosis (OR: 0.265, 95% CI: 0.086, 0.813, p < 0.001). After adjusting for confounders, a high‐quality diet was positively correlated with anti‐tuberculosis treatment outcomes (OR:0.957, 95% CI: 0.918,0.998, p = 0.039). Conclusion Compared with healthy adults, tuberculosis patients have poor diet quality with unreasonable diet structure. The insufficient intake of whole grains, vegetables, beans, aquatic products, meat and eggs and the excessive intake of pure energy food and solid fat suggests that the dietary structure of tuberculosis patients was unreasonable. This study provides an idea of the diet structure of tuberculosis patients.