〔Abstract〕 Objective To analyze the diagnostic efficacy of T cell spot test for tuberculosis infection (T-SPOT.TB) test in active tuberculosis (ATB). Methods A total of 200 suspected ATB patients admitted to Guangzhou Chest Hospital from February 2019 to February 2021 were selected. All patients received T-SPOT.TB and tuberculin skin test (TST), and the diagnostic efficacy of T-SPOT.TB and TST in diagnosing ATB was calculated and compared based on the final clinical diagnosis of the patients. Results The final clinical diagnosis of 200 patients showed the presence of ATB in 84 patients, all of whom had intrapulmonary tuberculosis. The accuracy and sensitivity of T-SPOT.TB in the diagnosis of ATB were significantly higher than those of the TST (P < 0.05), but there was no significant difference in the specificity of the two diagnostic methods (P > 0.05). Conclusion The diagnostic efficiency of T-SPOT.TB is higher than that of the TST, and the results of T-SPOT.TB can be used as an effective reference index for ATB screening.