Primary angiitis of the central nervous system （PACNS） is a rare immune-inflammatory disease confined to the small and medium blood vessels of the central nervous system， with unclear etiology and pathogenesis. The incidence of PACNS in the general population has not been accurately defined， and its clinical management is challenged by diagnostic difficulty， a high recurrence rate，and limited evidence supporting therapeutic interventions. The disease predominantly occurs in people aged 40‒60 years，with headache， cognitive impairment， and neurological deficits as the main clinical manifestations， which are non-specific.There are no characteristic indicators in laboratory tests， and cerebrospinal fluid examination can only rule out infection.Imaging findings include multiple infarctions and segmental vascular stenosis. Brain tissue biopsy is the gold standard for diagnosis. Clinically， the Calabrese and Mallek diagnostic criteria are often used， combined with supplementary criteria for stratified diagnosis. Treatment is based on glucocorticoids， with stratified induction， maintenance， and intensive therapy according to the type of involved blood vessels and disease severity， combined with immunosuppressants such as cyclophosphamide and mycophenolate mofetil. Biologics may be considered for refractory or recurrent cases.Long-term immunosuppressive therapy may reduce the risk of recurrence. Antiplatelet drugs， thrombolysis， and endovascular therapy can be used as needed. Currently， the diagnosis and treatment of PACNS still rely on diagnosis of exclusion and expert consensus，lacking high-level evidence.Future efforts should focus on exploring specific diagnostic markers and precise treatment regimens to promote standardized diagnosis and treatment.