The skin test for detecting tuberculosis refers to the PPD test. a positive PPD test indicates an infection with Mycobacterium tuberculosis or BCG vaccination, the cause of which there is no way to determine. If there are no lesions in the lungs, a positive PPD test is not a cause for concern and does not require special tests or treatment. If there is a lesion in the lung, further improvement of sputum test as well as blood test and other related indicators are needed. If the sputum test is positive, combined with the patient’s imaging examination, tuberculosis can be diagnosed. Active anti-tuberculosis treatment is needed, and the course of anti-tuberculosis treatment is about six months, and most patients can be cured after treatment.