Abstract: In order to improve the practicability of multi-wavelength optical pulse equipment, a stable dual-wavelength semiconductor fiber ring laser was proposed and demonstrated by using dual-wavelength principle. Effects of ring cavity dispersion, filter pulse-width and modulation depth on output pulse were discussed. Experimental results are that repetition rate of dual-wavelength pulses is 5.0GHz and typical pulse-width is 20ps. Dual-wavelength pulses have good side-mode suppression ratios of 29.1dB (at 1554.75nm) and 29.7dB (at 1557.21nm) with typical output powers of -6.7dBm and -6.1dBm respectively. Output spectra are very stable with peak power fluctuation less than 0.5dB. This study is of great significance for the study of terahertz source and multi-wavelength optical pulse equipment.