A new three-stage L-band erbium-doped superfluorescent fiber source(Er-SFS) is introduced. The structure utilizes the first-stage none-pumping,the second-stage forward-pumping and the third-stage backward-pumping. The influence of the pump wavelength,the length of erbium doped fiber (EDF) and the pumping ratio to the Er-SFS characteristics are studied numerically. Finally,a set of optimal parameters to simultaneously achieve a higher output power,lower ripple and lower cost as compared to the conventional L-band Er-SFS is given.