Clinically, by taking sputum and doing smear antacid staining, it is mainly used to check for the presence or absence of antacid bacilli, which is used to diagnose whether the patient is infected with Mycobacterium tuberculosis. In addition, it can also be used to clarify whether the infectiousness of tuberculosis patients still exists after treatment. Generally speaking, if the result is positive, it suggests the existence of Mycobacterium tuberculosis infection and a certain degree of infectiousness, and the patient belongs to the infectious source of tuberculosis bacilli that is being continuously discharged, and it is necessary to carry out standardized quarantine, and the systematic treatment with a combination of anti-tuberculosis drugs. If the result is negative, it does not exclude that the patient is infected with Mycobacterium tuberculosis, and should also be combined with the CT of both lungs, as well as PPD test and other joint diagnosis.