Novel magnetically separable heterogeneous g-C3N4/alpha-Fe2O3/CeO2 photocatalyst was effectively fabricated by a facile hydrothermal technique. Optical, structural, catalytic and antibacterial possessions of the intended catalyst were characterized. The photocatalytic activity evaluations of the heterogeneous g-C3N4/alpha-Fe2O3/CeO2 catalyst were evaluated for degradation of the MB dye irradiated with (420 nm < lambda) visible light. The g-C3N4/alpha-Fe2O3/CeO2 photocatalyst was originated to be an admirable catalyst for MB dye degradation progression. The consequences were specified that successfully uniting dispersed CeO2 nanoparticles with g-C3N4/alpha-Fe2O3 composite could enhance the visible-light accumulating capability, high specific surface area, retarded photogenerated charge carrier's mobility, and expressively improved photocatalytic ingredients of the system. The optimal g-C3N4/alpha-Fe2O3/CeO2 photocatalyst has provided 97.5% of MB dye photodegradation after 120 min with the degradation rate persistent is 0.0176 min(-1) which was almost 4.1 and 2.7 times greater than the g-C3N4 and g-C3N4/alpha-Fe2O3 nanomaterials under the irradiation of visible light. Trapping test verified\that the center dot-OH radicals are major reactive kinds in the catalytic reaction. A realistic mechanism for catalysis by the g-C3N4/alpha-Fe2O3/CeO2 nanocomposite was illustrated. Since, the g-C3N4/alpha-Fe2O3/CeO2 nanocomposite was originated to be stable, magnetically separated and recyclable with a tiny loss of activity, which are responsible for the sustainable photocatalytic developments of proficiently debasing in the organic pollutants. Moreover, g-C3N4/alpha-Fe2O3/CeO2 nanocomposite displays high catalytic antibacterial activities against S. aureus (G(+)) and E. coli (G(-)) bacteria.