Disclosed herein is an optical fiber laser device including a seed unit for providing at least two seed lights having different wavelengths; and an amplifying unit for amplifying the at least two seed lights. The amplifying unit includes: a preamplifying unit for amplifying the at least two seed lights by using excitation light of which the wavelength is shorter than the wavelengths of the seed lights; and a final amplifying unit to which no separate excitation light source is provided. The final amplifying unit amplifies the seed light having the longest wavelength by using the other seed light as excitation light with respect to the seed light having the longest wavelength among the at least two seed light.