Primary biliary cholangitis （PBC） is a chronic progressive autoimmune liver disease that is often comorbid with other connective tissue diseases （CTDs），and such comorbidity can significantly alter the natural course or clinical phenotype of PBC or CTDs，limiting available therapeutic drugs and complicating clinical decision-making. Due to the involvement of the interdisciplinary subjects of hepatology，rheumatology，and clinical immunology and a paucity of large-scale cohort data and in-depth basic research，there is a limited understanding of such comorbidity in clinical practice，which increases the complexity of clinical diagnosis and treatment. This article summarizes the comorbidity of PBC with common CTDs such as Sjögren’‍s syndrome，systemic sclerosis，systemic lupus erythematosus，and idiopathic inflammatory myopathies，and analyzes related immune mechanisms，clinical manifestations，diagnostic challenges，treatment strategies，and prognosis. It is expected to establish PBC-CTD comorbidity cohorts through future multidisciplinary collaborations，focus on genetic background，immune mechanisms，and multi-omics approaches，elucidate pathogenesis and novel therapeutic targets，and improve the prognosis of patients by optimizing treatment strategies through precision medicine and artificial intelligence.