Autoimmune liver disease overlap syndrome is a special type of autoimmune disease,and consensus has not been reached regarding the etiology and diagnosis and treatment. This paper reviews many aspects of overlap syndrome,such as etiology,pathogenesis,diagnosis and treatment,and its development process. In addition,the definition of this disease and the recent development of diagnosis and treatment are analyzed. It is pointed out that the pathogenesis of this disease is still not fully elucidated,and the standards for the diagnosis and treatment of this disease still need further discussion. Finally,the analysis showed that the clinical forms of AIH- PBC overlap syndrome can be varied,and early diagnosis and differentiation and reasonable treatment are the key points of current research.