A multi-wavelength Brillouin fiber laser with ultra-narrow line-width bidirectional feedback is intro. duced. A 10 km long single-mode fiber (SMF) connected with a 2×2 3 dB coupler is used as the Brillouin gain ringand a distributed feedback (DFB) semiconductor laser is taken as the Brillouin pump (BP). The output and feedback ofmulti-wavelength lasers are realized by two optical circulators without adding erbium-doped fiber linear gain structure.At the Brillouin pump power of 80 mW, stimulated Brillouin scattering is produced in 10 km long single-mode fiber (SMF). Therefore, multi-order Stokes reflection lights can be obtained. Stokes light output of 12 wavelengths with 0.088 nm wavelength spacing and 300 kHz output laser line width is observed except BP.