The first edition of "The Chinese expert consensus on the diagnosis and treatment of optic neuritis" have been published in Chinese Journal of Ophthalmology in 2014. Seven years later, more evidence-based medicine has been accumulated in the treatment of optic neuritis. It is necessary to update or formulate guidelines to guide clinical practice. Based on the methods and procedures for developing evidence -based guidelines, Neuro-Ophthalmology Group of Ophthalmology Branch of Chinese Medical Association and Evidence-based Medicine Centre of Lanzhou University/World Health Organization Collaborating Centre for Guideline Implementation and Knowledge Translation created the first "An evidence-based guideline for the diagnosis and treatment of demyelinating optic neuritis in China (2021)" , which aimed to improve the level of clinical diagnosis and treatments of demyelinating optic neuritis. This guideline proposes a new subtype classification of demyelinating optic neuritis to guide precision treatment. It also gives new suggestions about clinical treatment hotspots in the acute and chronic phases, including the application of immunosuppressants and rituximab and other biological agents.