Cu0.3Cd0.7CrFeO4 nanocrystals were obtained via co-precipitation strategy, and well-precisely scrutinized by X-ray diffraction (XRD), FT-IR spectra, and high resolution transmission electron microscopy (HRTEM) strategies. XRD investigation proved the evolution of the single-phase spinel structure for these nanocrystals existing in the Nano-regime. The teeny crystallite size R average value was 10.55 nm. FT-IR absorption spectra displayed the fundamental absorption bands that were related to their principle sites and main bonds. All the deduced parameters were affected by the coexistence of the Cu2+, Cd2+, Fe2+, Cr3+ and Fe3+ cations inside these nanocrystals. HRTEM images showed no accumulations for these nanoparticles, where the average particle size value was 11.11 nm and was slightly higher than the crystallite size R. Evaluation of photocatalytic activity for Cu0.3Cd0.7CrFeO4 Nano-spinel was acquired throughout the disintegration of Methylene Blue (MB) dye (1 × 10-3 M and 2 × 10-3 M) in aqueous medium under visible light irradiation using 100 Watt Tungsten lamp fixed at ~ 10 cm distance.