Bacteriological examination of sputum is a reliable indicator of the efficacy and infectivity of tuberculosis. Usually after 2-3 months of regular treatment of patients with multidrug-resistant tuberculosis, the amount of sputum bacteria can decrease significantly, while to achieve negative bacteriological examination of patients, the duration of treatment usually takes at least 6 months. During the treatment of multidrug-resistant tuberculosis, it is clinically recommended that patients with sputum should undergo monthly sputum culture of Mycobacterium tuberculosis, which in turn can determine the efficacy of treatment based on the number of sputum bacteria and whether the test results are negative, and facilitate timely changes in the patient’s treatment plan. At the same time, many patients clinically ask whether they are still infectious and whether they need to continue to be isolated from their families, and the clinical response can only be based on the patient’s sputum culture results. Only live bacteria can be cultured in the culture of Mycobacterium tuberculosis.