A novel two-stage cascade dual-backward pumped configuration using the synchronous pumping technique is presented to achieve a mean wavelength stable L-band superfluorescent fiber source (SFS). The effects of total fiber length, fiber length arrangement of the two-stage, and pump ratio on the output characteristics of the L-band SFS in terms of mean wavelength, linewidth, and output power are investigated. The results show that not only the output spectrum can be moved form C-band to L-band effectively but also the pump power independent mean wavelength operation can be achieved by using the two-stage cascade dual-backward pumped configuration. A SFS with linewidth of 47.3 nm, output power of 97 mW, and high mean wavelength stability is experimentally obtained with a pump ratio of 0.5 and 290 mW total pump power.