CuSn5–Al2O3 composite coatings were deposited on aluminum alloy 7075-T651 substrate by the low-pressure cold spraying technique. The effects of Al2O3 content (0–30 wt%) in feedstock on the microstructure, mechanical properties and tribological behavior under artificial seawater condition of the coatings were investigated. The results showed that the densification, hardness and bonding strength of the coatings were improved by the work hardening of Al2O3 particles. The friction coefficients were found in reasonable values, depending on the employed testing counterparts. The wear rate of the coatings decreased when rubbing against the counterparts. The wear mechanisms were abrasive and corrosive wear.