Tuberculosis skin test generally refers to the tuberculin test, the appearance of red halos may not be tuberculosis. Tuberculosis skin test results are interpreted in terms of the size of the nodules, not the size of the red halo, and the diagnosis of tuberculosis usually requires a combination of the patient’s medical history, clinical symptoms, and sputum culture tests. Tuberculin test is a test to diagnose hypersensitivity reaction due to Mycobacterium tuberculosis infection by intradermal injection of tuberculin and according to the skin condition of the injection site. After the injection of tuberculin test, the result of 72 hours is taken as the standard, and the size of the diameter of the local hard nodule is used as the criterion for determining the result, not the redness alone. The general positive reaction of tuberculin test indicates that the body has been infected with Mycobacterium tuberculosis, or has been vaccinated with BCG vaccine. If the diameter of the nodule is large, and there is blistering or necrosis locally, then it is a strong positive reaction, which suggests that there are active tuberculosis foci in the body. It is necessary to combine the specific condition of the patient, other auxiliary examination for comprehensive analysis and judgment. For example, patients with tuberculosis may have respiratory reactions such as coughing, coughing up sputum, or blood in sputum, and may be accompanied by systemic symptoms such as low-grade fever, fatigue, and night sweats. In addition, sputum culture is the “gold standard” for diagnosing tuberculosis. Patients should be diagnosed under the guidance of a doctor and should not blindly make their own judgment in order to avoid delaying their condition.