A novel trinary Co3ZnFe2O8 nanoparticle was synthesized using a photo-irradiation method with different solvents (water, chloroform, methanol, and ethanol). The Co3ZnFe2O8 nanoparticles were investigated by scanning and transmission electron microscopy measurements (SEM), Atomic force microscopy (AFM), and their crystal structure was obtained by the X-ray diffraction technique (XRD). The investigated results show that the Average size of Co3ZnFe2O8 nanoparticles ranges from 35 to 103 nm by different solvents. The X-ray diffraction proved the cubic shape of the prepared nano-samples with an average crystal size ranging from 8 to 22 nm. The Co3ZnFe2O8 nanoparticles were applied as a coating for corrosion protection of carbon steel in seawater. Finally, The corrosion production was equal to 74% at 298 K. It can be concluded that the prepared nanoparticles are highly effective in the protection