Os acromiale is a bony mass without osseous union formed due to non-fusion of the ossification centers of the acromion. The total incidence of the disease is about 7% globally, which is mainly manifested by pain at the acromion and normal passive movement of the shoulder joint, and is misdiagnosed as subacromial impingement and rotator cuff injuries. Patients with OA are currently treated in a variety of clinical settings, but the optimal treatment is controversial. Due to the low prevalence of OA and the fact that some patients are asymptomatic, accurate physical examination, imaging screening, and individualized treatment plans are important for early restoration of motor function. This article reviews the diagnosis and treatment of OA from the aspects of pathological anatomy, etiology and morbidity, symptomatic manifestations and imaging features, complications and differential diagnosis, and various surgical modalities that have been reported so far, and describes the advantages and disadvantages of various surgical modalities, and summarizes the types of applicability of different surgical modalities and internal fixation with the aim of providing the basis for the individualized and precise diagnosis and treatment of OA.