A dual-wavelength ring-cavity erbium-doped fiber (EDF) laser is designed based on two polarization beam splitters (PBSs) and a polarization controller (PC) performing gain equalization and polarization hole burning (PHB) effect. At room temperature, a stable dual-wavelength laser and a multi-output port laser which can simultaneously emit single-wavelength lasing and dual-wavelength lasing are obtained. The signal-to-noise ratios (SNRs) for single-wavelength outputs were 54.70 dB and 57.10 dB, with power fluctuations less than 0.038 mW and 0.029 mW, respectively. For dual-wavelength lasing, the SNRs were 59.63 dB and 59.25 dB, with power fluctuations less than 0.018 mW and 0.008 mW, respectively. The center wavelength drift was less than 0.006 nm for both single-wavelength and dual-wavelength outputs.