A suppressant effect for mode competition of multi-wavelengthlasing oscillations induced by deeply saturated effect in an ordinaryerbium-doped fiber ring laser (EDFRL) was observed and experimentallyinvestigated. Results show that the effect is helpful to obtain stablemulti-wavelength lasing at room temperature in the EDFRL, which offers anew and simple approach to achieve stable multi-wavelength EDF lasing.Stable two-and three-wavelength lasing oscillations were achieved based onthe effect in the ordinary EDFRL for the first time to our best knowledge.The multi-wavelength lasing oscillations were so stable integrated oversmaller than 1ms that the maximum power fluctuation over more than 30minutes of observation was less than 0.1 dB and 0.5 dB for two-wavelengthlasing with a spacing of 1.28 nm and 0.76nm, respectively.