The construction of computing power facilities requires optical fiber communication networks with high bandwidth, large capacity, and low time delay. However, optical fiber amplifiers with broadband gain, as key materials for relay amplification in optical transmission links, urgently need to be developed. Ultra-wideband gain optical fibers and their optical amplifiers have become research hotspots internationally. This paper elaborates in detail the luminescence characteristics of bismuth ions in different valence states and the research progress of bismuth-doped ultra-wideband gain fibers at home and abroad. It focuses on summarizing the preparation methods of bismuth-doped quartz fibers, the fiber amplification architecture, as well as their research progress in the fields of amplifiers and lasers.