Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory demyelinating disease of the central nervous system. Its pathogenesis is complex and mainly related to aquaporin 4 antibody. NMOSD typically follows a relapsing course leading to progressive aggravation of neurological deficits, making prevention of relapse being the key to NMOSD treatment. In addition to traditional non-specific immunosuppressants, new targeted drugs have gradually shown unique advantages in sequential treatment of NMOSD due to their significant efficacy and fewer adverse reactions. This article summarizes and reviews the pathogenesis of NMOSD and the safety and efficacy of immunosequential therapy drugs.