Weakly positive antibody test for Mycobacterium tuberculosis suggests that the patient has been infected with Mycobacterium tuberculosis or has been injected with BCG vaccine. The specific condition needs to be determined by combining clinical symptoms and other examinations, and the common causes include recent infection, previous infection with immune system, and vaccination. 1. Recent infection: weakly positive antibody test, accompanied by low fever, night sweats, and lesions in the lungs detected by chest CT, suggesting that it is a recent infection. 2. Previous infection: If you have been infected with tuberculosis before and now you have antibodies in your body, you will also have related conditions, usually without obvious clinical symptoms, and most of the lesions in your lungs are old lesions through lung CT examination. 3. Vaccination: the body does not have any clinical symptoms, through the lung CT examination and sputum culture are negative, suggesting that the body has immunity to tuberculosis after vaccination. Weakly positive antibody to tuberculosis bacillus, accompanied by obvious symptoms such as low fever, night sweats, coughing, etc., need to be admitted to the hospital in time for medical examination, after diagnosing the specific condition, under the guidance of the clinician to carry out standardized treatment, to avoid delays in the condition.