Application of Z-scheme heterojunction systems toward mimicking natural photosynthesis is an efficient methodology to improve solar energy conversion. Herein, we successfully develop a Z-scheme heterojunction photocatalyst by using Au nanoparticles as electron mediator to couple ferroelectric-BaTiO3 nanowires and g-C3N4. This rationally constructed Z-scheme system with the extra surface plasmon resonance (SPR) effect of Au nanoparticles and ferroelectricity of BaTiO3 shows the significantly enhanced generation and separation efficiency of photogenerated carriers and the high reduction ability of elections. Accordingly, it exhibits the high photocatalytic performance for both H-2 evolution and RhB degradation. In particular, its H-2 evolution rate is about 18 times to that of g-C3N4 alone. The reasonable interfacial charge transfer mechanism discovered in this work provides a new approach to understanding and designing other efficient Z-scheme heterojunction systems.