Abstract: Objective: To observe imaging features of high-resolution CT(HRCT) in patients with active tuberculosis and diagnostic value of their combination with T cell spot test-tuberculosis(T-SPOT.TB) and serum tuberculosis antibody(TB-Ab). Methods: During the period from January 2016 to July 2019, 198 patients with suspected active tuberculosis who were admitted to the hospital were enrolled. After admission, all underwent HRCT, T-SPOT.TB and TB-Ab examination. HRCT features of active tuberculosis and diagnostic efficiency of their combination with T-SPOT.TB and TB-Ab were summarized. Results: HRCT images of the 112 patients diagnosed with active tuberculosis showed lobular central nodules and tree-in-bud signs in 92 cases(82.14%), thickened bronchial walls in 82 cases(73.21%), lung consolidation in 86 cases(76.79%), cavity signs in 82 cases(73.21%), linear shadow in 81 cases(72.32%), liquid bronchial signs in 81 cases(72.32%) and ground-glass opacity in 64 cases(57.14%). The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of HRCT for diagnosis of active tuberculosis were 77.67%, 82.56%, 79.80%, 85.29% and 73.96%, respectively. The above 5 indexes of T-SPOT.TB and TB-Ab were(95.54%, 90.70%, 93.43%, 93.04%, 93.98%) and(28.57%, 82.56%, 52.02%, 68.09%, 44.10%), respectively. The above 5 indexes of combined diagnosis were 97.32%, 95.35%, 96.46%, 96.46% and 96.47%, respectively. Conclusion: HRCT specific signs of active tuberculosis include lobular central nodules, tree-in-bud sign, bronchial wall thickening, lung consolidation and cavity signs, which are conducive to their diagnosis and identification. The diagnostic efficiency of T-SPOT.TB is the highest for active tuberculosis. For cases that cannot be confirmed, T-SPOT.TB can be combined with HRCT and TB-Ab, so as to increase detection rate of active tuberculosis.