Due to the low efficiency of traditional communications and many problems, the development of optical fiber communications is currently necessary. Among them, fiber laser is the core of fiber communication, and the higher the output band of a fiber laser, the more information it carries, and the information that can be transmitted increases accordingly. Therefore, the primary goal is to develop a fiber laser with high-band output. At present, research on high-band output fiber lasers is being carried out at home and abroad. Domestic research focuses on the selection of fiber media; foreign research focuses on random fiber lasers. This article adopts the domestic research route, based on the premise that vanadium ions can emit laser wavelengths that include the L+ band when performing energy level transitions. At the same time, vanadium-doped gallium lanthanum sulfide glass has good functions of absorbing pump light and emitting lasing light. Therefore, this article mainly discusses the design of vanadium-doped fiber lasers using vanadium-doped gallium sulfide as the gain medium under simulation conditions to achieve high-band output of fiber lasers.