The (PS-In2O3/ ZnCoFe2O4) nanocomposites have been prepared by using solution casting method. The structural, optical and dielectric properties of (PS-In2O3/ ZnCoFe2O4) nanocomposites have been studied to use it for different optoelectronics applications. The structural properties include FTIR, optical microscope and SEM. The results of optical properties for (PS-In2O3/ ZnCoFe2O4) nanocomposites showed that the absorbance, absorption coefficient, refractive index, extinction coefficient, dielectric constants and optical conductivity of (PS-In2O3) nanocomposites were increased with the increase in ZnCoFe2O4 nanoparticles concentrations while the transmittance and energy band gap were decreased with the increase of the ZnCoFe2O4 nanoparticles concentrations. The(PS-In2O3/ ZnCoFe2O4) nanocomposites have high absorbance in the UV-region. The results of dielectric properties showed that the dielectric constant, dielectric loss and A.C electrical conductivity of (PS-In2O3) nanocomposites increase with increase in ZnCoFe2O4 nanoparticles concentrations. The dielectric constant and dielectric loss decrease while the electrical conductivity increases with an increase in frequency.