Objective To explore the auxiliary diagnosis value of two commonly used immunological indicators for tuberculosis, purified protein derivative skin test (PPD test) and tuberculosis-interferon gamma release assay (TB-IGRA). Methods A total of 171 cases of suspected tuberculosis patients who were treated in the outpatient department of our center from January 2017 to January 2021 were collected. All cases underwent PPD test and peripheral blood TB-IGRA. The cases were divided into tuberculosis groups (TB group) and non-tuberculosis group (non-TB group). There were 98 cases in the TB group and 73 cases in the non-TB group. The accuracy, sensitivity, and specificity of PPD test and TB-IGRA for tuberculosis diagnosis were compared between the two groups. Results The accuracy, sensitivity, and specificity of TB-IGRA for tuberculosis diagnosis were 94.2%, 93.9% and 90.4% respectively, which of PPD test for tuberculosis diagnosis were 77.2%, 84.7% and 76.7% respectively. The accuracy and specificity of TB-IGRA were statistically different from those of PPD test (χ²=20.034,P<0.05 and χ²=5.176,P<0.05, respectively). The sensitivity of TB-IGRA was higher than that of PPD test, but the difference was not statistically significant (χ²=0.948,P>0.05). The differences of TB-IGRA and PPD test results between the two groups were statistically significant (χ²=132.77,P<0.01 and χ²=47.9635,P<0.01). Conclusion Both TB-IGRA and PPD test had good auxiliary diagnostic value for tuberculosis; the introduction of TB-IGRA had greatly improved the accuracy and specificity of the diagnostic test, but it is still necessary to further explore its diagnostic criteria to better serve the clinical use.