High-power fiber lasers, compared to traditional solid-state lasers, have obvious advantages such as compact structure, high conversion efficiency, good beam quality, and ease of heat dissipation. They have significant application prospects in many fields, including advanced manufacturing, military defense, scientific research, and medicine, and are a research hotspot in the international laser technology field. Thanks to the continuous development and improvement of double-clad fiber drawing technology and high-power semiconductor laser manufacturing processes, the conversion efficiency and output power of fiber lasers have been greatly enhanced. Breakthroughs have been made in various key technologies, such as new structural designs for doped fibers, various coupling technologies including end and side pumping, and laser beam combining techniques. Especially driven by the application demands in industrial processing, directed energy weapons, long-range telemetry, and lidar, foreign research institutions and companies represented by IPG Photonics Corporation, Nufern, nLight Corporation, SPI Lasers UK, and TRUMPF Group in Germany have actively developed high-power fiber lasers. They have successively launched commercial fiber laser products with continuous wave powers ranging from tens of watts to tens of kilowatts, and some of these products are subject to restrictive export or embargo to China. Although domestic research on high-power fiber lasers started later than abroad, rapid development has been achieved in recent years. Many universities, research institutes, and companies have participated in the research and development of fiber lasers and have successively launched a variety of mature products.