The characteristics of all-fiber gas Raman light source based on hydrogen-filled hollow-core photonic crystal fiber pumped with Q-switched fiber laser are investigated theoretically and experimentally. The wavelength of the Stokes frequency-shift wave is 1135.7 nm with the Q-switched pump pulses at 1064.7 nm. Both our theoretical and experimental results show that the generated Stokes pulse is much narrower than the pump pulse, and the generated Stokes pulse duration increases with the single pulse energy of the pump pulses. Moreover, by choosing narrower pump pulses, the Raman threshold pump energy may decrease and the conversion efficiency may increase. For the 125 ns pump pulses with the repetition rate of 5 kHz, the Raman threshold pump energy and the conversion efficiency at the Raman threshold are measured to be 2.13 μJ and 9.82% in experiments.