The main pathogenic bacteria are pneumococcus, Haemophilus influenzae, staphylococcus and so on. Infection mainly through three ways: 1, the most common way of the Eustachian tube (1) acute upper respiratory tract infection: bacteria through the Eustachian tube invasion of the middle ear, resulting in infection. Normal tympanic membrane acute suppurative otitis media tympanic membrane (2) acute infectious diseases: such as scarlet fever, measles, whooping cough, etc., through the Eustachian tube pathway can be concurrent with the disease; acute suppurative otitis media can also be localized manifestations of the above infectious diseases. This type of lesion often reaches deep into the bone, resulting in severe necrotic lesions. (3) Swimming or diving in sewage, improper blowing of the Eustachian tube, blowing the nose or nasal treatment, etc., bacteria invade the middle ear through the Eustachian tube. (4) Infants and young children are more susceptible to middle ear infections through this route due to the anatomical and physiological characteristics of the Eustachian tube. Improper breastfeeding position, such as lying down to suckle, milk can flow into the middle ear through the Eustachian tube. 2, the external auditory canal tympanic membrane pathway does not meet the aseptic operation of tympanocentesis, tympanic tube placement, tympanic membrane trauma, pathogenic bacteria from the external auditory canal directly invade the middle ear. 3.Bloodstream infection is rare. Second, the main symptoms are as follows: 1, earache, most patients with tympanic membrane perforation before the pain is intense, not sleep; such as pulsating throbbing pain or stabbing pain, can be radiated to the same side of the head or teeth, tympanic membrane perforation pus and pain relief. A few patients may have no obvious earache symptoms. 2, hearing loss and tinnitus in the early stage of the disease, patients often have obvious ear boring, low-pitched tinnitus and hearing loss. Deafness may be reduced in the later stage when the tympanic membrane is not perforated. If the earache is severe, the hearing impairment may be neglected. Some patients may be accompanied by vertigo. 3, pus flow after perforation of the tympanic membrane, there is liquid out of the ear, initially blood and water pus, and later become purulent secretion. 4.Systemic symptoms vary in severity. There may be cold, fever, lassitude, and poor appetite. Pediatric elective deep symptoms are heavier, often accompanied by vomiting, diarrhea and other similar gastrointestinal symptoms. Once the tympanic membrane is perforated, the body temperature will gradually decrease, and the systemic symptoms will be significantly reduced. Third, treatment: control infection, smooth drainage, remove the disease because of its treatment principle. Disease prevention: 1, popularize the correct nose blowing and breastfeeding health knowledge. 2, active prevention and treatment of upper respiratory tract infection and respiratory infectious diseases. 3.People with gauge perforation or tympanic tube placement should avoid participating in useful activities that may lead to tympanic water intake.