To address the issues of narrow gain bandwidth and complex structure in current fiber amplifiers, a 2 μm ultra-wideband PbS quantum dot fiber amplifier is fabricated. Firstly, PbS quantum dots with an average diameter of approximately 9.2 nmare synthesized through the organometrical approach and deposited on the surface of the optical fiber cone region by the opticaldeposition method. Subsequently, the PbS quantum dots coated in the conical region of the fiber are excited by a pumping lightsource to emit photons with the same wavelength as the signal light in the 2 μm band, thereby achieving the amplification of theoptical signal. The test results indicate that the optical fiber amplifier can attain a gain of 10.1 dB within the band of 1 900~2 100nm, and the gain bandwidth is approximately 200 nm.