A Cu₂O/Pt/BiVO₄ heterojunction was prepared by successively depositing Pt and Cu₂O nanoparticles on {010} facets of BiVO₄, showing much higher photocatalytic activity in hydrogen evolution than that constructed by random deposition of Cu₂O on all facets of BiVO₄ particles. Photoluminescence spectroscopy revealed that the facet-selective Cu₂O/Pt/BiVO₄ arrays effectively promoted charge separation of the BiVO₄ host. A band alignment was consequently presented to illustrate the interface charge flow in the heterojunction. This work demonstrates the roles that facets played in semiconductor heterojunctions applied to photocatalytic reactions.