The reason why otitis externa is easy to recur or prolonged may be that the patient himself has systemic chronic diseases, poor resistance or the local cause of the disease has not been removed for a long time. Otitis externa recurrence reasons are ① frequent ear digging, water in the external auditory canal, resulting in trauma to the external auditory canal and local resistance to decline; ② patients themselves have diabetes and other chronic systemic diseases. Prevention of otitis externa need to do ① improve lifestyle habits, eliminate ear digging, swimming or cleaning the ears after bathing, to keep the ear canal dry and hygienic and drainage; ② active treatment of primary illnesses, enhance the body’s immunity. When otitis externa recurring, you should consult a doctor in time, under the guidance of the doctor to improve the relevant diagnosis and treatment.