A widely tunable ring cavity fiber laser using 1480 nm high power LDs as forward and backward pumping is discussed. It also takes the Bi-based Er-doped fiber as the gain media,and uses the rotating F-P tunable filter and two band-pass filters as the wavelength tuning device. The laser can cover 100 nm(1523～1623 nm) tuning range controlled by software. The output power is above 2 dBm. The 3 dB bandwidth is below 0.1 nm. The wavelength repetition precision is below 0.01 nm.