A weakly positive Mycoplasma antibody does not necessarily mean pneumonia, but a test for Mycoplasma antibody is an indicator for the diagnosis of Mycoplasma pneumoniae infection. When the antibodies against Mycoplasma pneumoniae are weakly positive, especially when the IgM antibodies are weakly positive, it mostly indicates mycoplasma infection, but it can form upper respiratory tract infection, bronchitis, and also urinary tract infection, not necessarily the presence of pneumonia. In particular, when a new inflammatory lesion infiltration is seen on chest imaging, and the patient also has clinical symptoms of the respiratory system, such as dry cough, chest tightness, chest pain, chills, fever and other clinical symptoms, the formation of mycoplasma pneumonia should be considered, so the diagnosis of pneumonia formation must be made only when there is an inflammatory lesion infiltration on chest x-ray or CT examination.