In this study, the ternary composite material of magnesium ferrite-titanium dioxide/reduced graphene oxide (MgFe2O4–TiO2/rGO−MFOTG) was successfully synthesized via a simple hydrothermal method from MgFe2O4–TiO2 (MFOT) and graphene oxide (GO). In particular, the MFOT was fabricated via the co-precipitation method with chitosan as a stabilizer. Meanwhile, the GO was fabricated via the improved Hummers’ method. The characterization results indicated that the MFOT was successfully synthesized and evenly distributed onto the surface of the rGO sheets with the average size ranging from 50 to 100 nm. The prepared material possessed a photodegradation efficiency of 95% for methylene blue under the radiation of UV and visible light for 60 and 70 min, respectively. Besides, the MFOTG exhibited a good catalysis performance for the photoproduction of H2O2 under the illumination of visible light with a productivity of 153.63 ± 2.76 mM/g for 30 min. The aforementioned results confirmed the potential applications of the resulting MFOTG in the environmental treatment and production of H2O2.