In the face of the demand for increased communication capacity of fiber optic communication and the requirement for accuracy and stability of various fiber optic devices, the light source, as one of the key devices, is also required to have higher bandwidth and output power. In this paper, this study model and simulate the output spectrum of a quantum-doped optical fiber light source in the range of 1200nm to 1700nm. The rate equation and power propagation equation are established based on the energy level structure of quantum dots. MATLAB solves the numerical model to obtain the output spectra of quantum dot-doped optical fiber light source under different variables. The fiber length, doping concentration, and pumping optical power was further varied to study the effects of several variables on the peak output spectrum. The results show that the fiber length and doping concentration increase and then decrease the peak value of the output spectrum while the pump power increases the peak value of the output spectrum. A pump power of 200 mW was chosen to obtain good experimental results at a fiber length of 3 m and a doping concentration of . The maximum output power is 4.9 mW, and the spectral line width is about 80 nm. The maximum output power is 69 mW, and the spectral line width is about 100 nm at a fiber length of 4 m and a doping concentration of  with a pump power of 400 mW.