The invention provides a broadband light source system using C waveband erbium-doped fibers to generate a C+L waveband. The broadband light source system using the C waveband erbium-doped fibers to generate the C+L waveband comprises a pump source, a coupler, a first wavelength division multiplexer, the first erbium-doped fiber, the second erbium-doped fiber, a second wavelength division multiplexer, an annular lens and an isolator, wherein the pump source and the coupler are connected in sequence, the first wavelength division multiplexer is connected to the second path of output of the coupler, the first erbium-doped fiber and the second erbium-doped fiber are connected to the first wavelength division multiplexer, the second wavelength division multiplexer is connected to the first erbium-doped fiber, the annular lens is connected to the first path of output of the second wavelength division multiplexer, and the isolator is connected to the first wavelength division multiplexer, the second path of output of the second wavelength division multiplexer is connected to the first path of output of the coupler, the first erbium-doped fiber and the second erbium-doped fiber are different in length and the same in doping concentration, and the power of the first path of output of the coupler is lower than that of the second path of output of the coupler. According to the broadband light source system using the C waveband erbium-doped fibers to generate the C+L waveband, a high-flatness C+L waveband broadband light source with the single-ended pump spectrum compensation function is simple in structure, the cost is low, a high-flatness light output ASE light source can be obtained, and the broadband light source system using the C waveband erbium-doped fibers to generate the C+L waveband has important theoretical significance and application value.