A photosensitive polarization-maintaining erbium-doped fiber was fabricated experimentally and a high efficiency resonance cavity was set up by writing three fiber Bragg gratings on this fiber using UV laser. The mono-wavelength laser with mean output power of 9.20dBm and mean wavelength of 1554.554nm was produced by pumping at a power of 23.617dBm and wavelength of 976nm. The fluctuations of output power and wavelength were less then ±0.05dB and ±0.0015nm for a test time of 800min, respectively, at room temperature.