Sinus mucosal cysts are formed as a result of blockage of the sinus mucosal glandular ducts or inflammation and metaplasia of the mucosa. There is often no special discomfort, and occasionally there is persistent dull pain in the head and a feeling of pressure in the cheeks. Sinus mucous cysts are mostly caused by the blockage of mucous glands in the mucous membrane, and the secretions in the glands are trapped under the mucous membrane to form cysts. Also known as mucus retention cysts; there is also a mucosal inflammation or metaplasia, capillary exudation of plasma retention in the submucosal connective tissue gradually expanded to form cysts, also known as sinus plasmacytoid cysts, It often occurs unilaterally, and is more common in maxillary sinus. It occurs slowly, and can be accompanied by lifelong, and usually ruptures naturally after the volume increases, and can be seen as a yellowish liquid outflow, sometimes accompanied by symptoms such as soreness and swelling of the nose, persistent dull pain in the head, and a feeling of compression in the cheeks. Most patients are asymptomatic, usually found incidentally during examination, feasible sinus CT, or brain MRI, temporal bone CT may also be scanned; asymptomatic people do not need special treatment, mucosal cysts are larger or cause persistent dull head pain, cheek pressure, etc., can be applied to nasal sprays or endonasal endoscopic surgical treatment. In conclusion, when there are sinus cysts, it is recommended to consult a doctor in time for clear diagnosis and treatment.