Formaldehyde does not normally cause Mycoplasma pneumoniae infection. Mycoplasma pneumoniae is a pathogenic bacteria, often found in the oral and nasal secretions of mycoplasma-infected people, and can enter the human body through respiratory transmission, direct or indirect contact, and so on, causing respiratory tract and lung lesions. Formaldehyde is an organic compound, although belongs to the harmful gas, but generally does not cause Mycoplasma pneumoniae infection. Therefore, formaldehyde generally does not cause pneumonia and mycoplasma infection. It is recommended that patients with pneumonia and mycoplasma infection go to the hospital in time to avoid delay.