In this research, we report a simple and inexpensive path for synthesis of magnesium titanate (MgTiO3) and magnesium ferrite (MgFe2O4) nanostructures. MgFe2O4 were synthesized using a microwave-assisted method. The impact of time and microwave radiation power on the morphology of magnetic nanoparticles was studied. Magnesium ferrite-magnesium titanate (MgFe2O4–MgTiO3) nanocomposite was prepared by sol-gel method. The morphology and particles size of samples were studied by scanning electron microscopy (SEM). The crystallinity and purity of products were checked using X-ray diffraction technique. The magnetic property of the produced material was obtained by vibrating sample magnetometry (VSM). The photocatalytic activity of products for degradation of different organic dyes, such as acid black and acid brown under visible light was investigated. The results show a good photo-degradation for organic dyes under the radiation of visible light. Our results indicate that, MgFe2O4–MgTiO3 nanocomposite can be employed for effective charge separation, and lifetime increase of the charge carriers. This product exhibits photocatalytic activity higher than which is reported for MgTiO3 nanostructures.