It is imminent to develop and utilize solar energy to solve the increasingly serious environmental crisis. In order to improve the utilization rate of sunlight and the performance of photocatalysts, this work innovatively proposed to prepare Z-Scheme MoS2/RGO/Fe2O3 ternary composites by an in-situ growth method combined with a surface electrostatic adsorption method.MoS2/RGO hetero-structured binary composites were firstly synthesized by a hydrothermal method, and then all-solid-state Z-Scheme MoS2/RGO/Fe2O3 photocatalyst was constructed via adjusting the solution pH value to create the same charges of MoS2 and Fe2O3 and the opposite charges of RGO and MoS2. According to the results by scanning electron microscopy and transmission electron microscopy, MoS2 nanosheets and Fe2O3 nanoparticles are uniformly distributed on the surface of two-dimension RGO, and MoS2 nanosheets and Fe2O3 nanoparticles display a stable hetero-structure onto RGO nanosheets. The RGO-based all-solid-state Z-Scheme photocatalyst possesses a superior photocatalytic reduction degradation performance under the simulated solar-driven illumination. Especially, the all-solid-state Z-Scheme photocatalyst MR0.43F has the optimum photoreduction degradation efficiency within 60 min for heavy metal Cr (VI) in a solution as a degradation indicator, which is 1.5 times greater than that of binary MoS2/RGO composites. The all-solid-state Z-Scheme photocatalyst has wide-spectrum absorption, high separation efficiency of photogenerated carriers and surface chemical reaction efficiency, thus improving the photocatalytic properties.