A novel all-fiber and switchable quintuple-wavelength erbium-doped fiber laser based on a chirped fiber grating was proposed and demonstrated experimentally.The laser used simple linear cavity structure.A length of highly-doped erbium fiber was used as gain medium.A Sagnac loop with a wide-band chirped fiber grating was used as the cavity mirror of resonant cavity,which acted as a comb filter.Another cavity mirror acted as wide-band fiber reflective mirror.Through properly adjusting polarization controller in the loop,maximum quintuple-wavelength laser output and four kinds of different laser output modes can be obtained.All excitation lines have optical SNR greater than 32 dB,line width less than 0.6 nm and peak power difference less than 8 dB.