Secretory otitis media (SOM) refers to non suppurative otitis media characterized by conductive hearing loss and tympanic effusion without acute inflammatory manifestations. Its etiology and physiological mechanisms are complex, with ear symptoms such as ear tightness, tinnitus, and earache being the main symptoms, which can occur in all age groups, and preschool children are the high-risk population. At present, the etiology and pathogenesis of secretory otitis media have not been fully elucidated. Analyzing the composition of ear effusion in SOM is a common method to study the etiology and pathogenesis of SOM, and is also an important way to guide clinical treatment. This article compares and summarizes the research progress of the composition of ear effusion in secretory otitis media published at home and abroad.