A MnO2/CdTiO3 is prepared by a simple chemical method. The organic compound such as antibiotics is a contaminant found in large amounts in pharmaceutical industrial wastewater. Pharmaceutical compounds are toxic. The nano‐product was characterized by SEM, XRD, XPS, DLS and UV–vis DRS revealed that the MnO2 nanoparticles were supported on the CdTiO3 surface. The crystallite size was found as 72.11 nm, and 38.13 nm for CdTiO3, and MnCdTi‐1 nanocomposites, respectively. The prepared catalyst was used for photo‐degradation of cephalexin under UV light irradiation. The result implies the complete degradation of cephalexin was carried out at 80 min for MnCdTi‐2 nanocomposites (88.88%) due to this catalyst has the lowest band gap compared to the other catalyst. The MnO2/CdTiO3 was selected for fungicidal and bactericidal efficiency against Aspergillus flavus, and candida albicans and Escherichia coli, and Staphylococcus aureus. The MnO2/CdTiO3–2 has great activity is compared with the other MnO2/CdTiO3–0 and MnO2/CdTiO3–1 samples.