We investigate a photonic crystal fibre Raman laser using fibre Bragg grating pairs as cavity mirrors. The threshold pump power is up to 0.65 W by decreasing the cavity loss and using a photonic crystal fibre with high Raman gain coefficient. A maximum continuous-wave output power of 2.7 W is obtained at the maximum incident pump power of 5.6 W. The corresponding optical conversion efficiency and the slope efficiency are about 48% and 56%, respectively.