The diagnosis of tuberculosis consists of a sputum test for antacid bacilli and a chest imaging examination, both of which can be combined to make the diagnosis of tuberculosis. A positive sputum test for antacid bacilli indicates that the patient’s tuberculosis is in an active stage and requires standardized anti-tuberculosis treatment. Once the chest CT indicates a shadow in the lung, it is necessary to exclude shadows caused by other lung infections. If the shadows are considered to be caused by tuberculosis infection, they will be polymorphic, occurring in the apical, posterior, and dorsal segments of the lung. Shadow changes with polymorphic exudates, proliferation, fibers, calcifications, cavities, and pleural thickening are typical of pulmonary tuberculosis. If accompanied by cough, sputum, hot flashes, night sweats, blood in the sputum, and body wasting, the patient can be judged to have possible pulmonary tuberculosis in combination with the lung shadow. Further sputum check antacid bacillus test needs to be given for early administration of standardized anti-tuberculosis treatment. Therefore, the imaging diagnosis of pulmonary tuberculosis, including the diagnosis of having a shadow in the lung.