The removal of formaldehyde (HCHO) from indoor air is of great importance to reduce health risks and improve indoor air quality. In this study, nano-Cu₂O-loaded paper with superior photocatalytic activity under visible light for the removal of HCHO was fabricated through a green, simple, and fast in situ synthesis method. The optimum preparation conditions for nano-Cu₂O-loaded paper were as follows: 2 g (oven-dry basis) cellulose fibers, CuSO₄ dosage 8 g, NaOH dosage 1.6 g, temperature 2+ 80℃, 60 min for Cu²⁺ absorption, and 60 min for reaction. Under the optimum conditions, the Cu₂O deposition ratio approached 30% and the nano-Cu₂O-loaded paper exhibited a catalytic efficiency of approximately 97% for HCHO removal. The photocatalytic capacity of nano-Cu₂O-loaded paper for HCHO removal had a positive correlation with the deposition ratio of nano Cu₂O particles. Excellent antibacterial property of nanoCu₂O-loaded paper against Staphylococcus aureus and Escherichia coli was also confirmed. Moreover, nano-Cu₂O-loaded paper was proven to be hydrophobic.