Supplementary material includes sample synthesis, experimental details, the photocurrent after poling at positive polarization voltage under 0.2 GPa, the evolution of the FeO4 tetrahedron in BaFe4O7 under high pressure, schematic diagram of ferroelectric photocurrent relaxation process when the sample after poled by upward Ep , the summary of the band gap and residual polarization of film ferroelectric photovoltaic materials (FPVs) and bulk FPVs.