Objective To analyze and compare the auxiliary value and significance of γ-interferon release assay (IGRA) in the diagnosis of tuberculosis. Methods A retrospective analysis was conducted to collect the test results of 462 suspected tuberculosis patients who underwent IGRA detection in the outpatient department of Tianjin Tuberculosis Control Center from January 2020 to December 2021. According to the diagnostic results, they were divided into a tuberculosis group of 229 cases (203 cases of pulmonary tuberculosis and 26 cases of extrapulmonary tuberculosis) and a non-tuberculosis group of 233 cases. The auxiliary diagnostic value of IGRA for tuberculosis was analyzed and compared with two methods of Mycobacterium tuberculosis culture and Xpert MTB/RIF. Results The positive rates of IGRA, Mycobacterium tuberculosis culture, and Xpert MTB/RIF in TB patients were 76.42%, 29.26% and 40.62%, respectively, compared with the non-TB group (38.20%, 0.00%, 0.00%), with statistically significant differences (P<0.001). The sensitivity, specificity, positive predictive value, and negative predictive value of IGRA alone in the detection of tuberculosis were 76.42%, 61.80%, 69.29%, and 72.73% respectively, those of Mycobacterium tuberculosis culture were 29.26%, 98.28%, 94.37%, and 63.43%, and those of Xpert MTB/RIF were 40.60%, 100%, 100%, and 63.14%. The positive rates of IGRA were 76.85% and 73.08% in patients with pulmonary tuberculosis and extrapulmonary tuberculosis, respectively, with no statistical significance (P>0.05). The positive rates of IGRA in bacterial positive patients and non-tuberculosis patients were 79.34% and 38.20%, respectively, with statistical significance (χ2=54.526, P<0.001). The positive rates of IGRA in patients with and without tuberculosis were 73.15% and 38.20%, respectively, with significant difference (χ2=36.456, P<0.001). Conclusions IGRA has a relatively high sensitivity in the diagnosis of tuberculosis and also has certain advantages in the screening of extrapulmonary tuberculosis and mycobacterium-negative It provides important reference basis for the clinical diagnosis of tuberculosis.