In the present study, describe a facile synthesis of Copper selenate (CuSeO4) decorated β-cyclodextrin (As: β-CD IC/CuSeO4) nanocomposite for the utilization of photocatalytic activity, anti-oxidant activity, and antimicrobial activity. CuSeO4 nanocomposites are synthesised via simple and green methods using β-cyclodextrin as reducing agents. When utilised as an antibacterial agent against a Gram-positive and a Gram-negative bacterium, the As: β-CD IC/CuSeO4 nanocomposite is a remarkable material in suppressing the challenged bacterial strains. The As: β-CD IC/CuSeO4 composite has shown exceptional activity with an 18-mm inhibitory zone at different concentrations of 50 mg/ml, 75 mg/ml, and 100 mg/ml, and maintains significant antibacterial efficacy for 72 h, proving its sustainable performance for a long-life period.