We propose to perform neutron diffraction experiments under high-pressure on a frustrated antiferromagnet CuFeO2 using WISH in combination with hybrid-anvil-type high-pressure device (Fig. 1) developed by Japan Atomic Energy Agency (JAEA).[1] In a preliminary experiment on WISH, we have succeeded in measuring temperature dependence of a few magnetic reflections of CuFeO2 down to 1.5 K under 1.4 GPa. The experiment proposed here should clarify the pressure effect on the various magnetic orderings of CuFeO2 under extended pressure region up to 9 GPa.