A method for manufacturing an optical fiber emitting plasma light includes a coating removal step of removing a coating of an optical fiber; a photocatalyst application step of applying a photocatalyst to an end surface of a core layer of the optical fiber from which the coating has been removed through the coating removal step; and a molding step of molding the end surface of the core layer into a curved surface by applying a laser to the core layer of the optical fiber applied with the photocatalyst through the photocatalyst application step. The method for manufacturing an optical fiber including the above processes may be effectively used for therapy such as plasma disc coagulation therapy (PDCT) by converting the applied laser light into plasma light.