Introduction: With the development of antibody detection technology, Gamma-Aminobutyric Acid (GABA) B receptor encephalitis is a known autoimmune disease. This paper describes a patient with refractory hypotension who suffered GABA B receptor autoimmune encephalitis. Case Report: We describe a 63-year-old man with GABA B receptor autoimmune encephalitis who had hypotension on day 17 of the disease onset. Despite two rounds of immunoglobulin administration, high-dose intravenous steroid injections and immunosuppressive therapy on day 35 of hospitalization, psychiatric symptoms and seizures were significantly improved; however, the patient's blood pressure remained low. Conclusion: This case study and literature review investigated the impairment of autonomic nerve function and its subsequent management in patients with GABA B receptor autoimmune encephalitis.