A novel BiVO4/RGO/Ag3PO4 ternary composite photocatalyst was fabricated through a two-step method of solvothermal assisted in situ ion sequential deposition method. The morphological structure, composition and optical properties were characterized by SEM, XRD, FT-IR, XPS, PL and UV-vis. The photocatalytic activities were assessed by the photocatalytic degradation process of Rhodamine B (RhB) and 4-nitrophenol (4-NP), and its photocatalytic mechanism was analyzed by conducing active radicals trapping experiments. The as-obtained BiVO4/RGO/Ag3PO4 composite photocatalysts exhibited enhancement in photocatalytic activities compared with the pure BiVO4, Ag3PO4 and BiVO4/Ag3PO4 composite photocatalysts, which can degrade 98.2% of RhB and 82.1% of 4-NP in 45 min under the simulated sunlight irradiation when the mass ratio of Ag3PO4 to BiVO4/RGO composites was 0.6:1. The photo-generated holes (h(+)) and the superoxide radicals (O-2(-)) radicals were the dominant active species during the photocatalytic degradation process. The enhancement in photocatalytic performance can be ascribed to the synergistic effect of BiVO4 and Ag3PO4, and the incorporation of reduced graphene oxide (RGO) which can promote the transfer and separation of photogenerated carriers at their interfaces.