In order to realize direct electroless nickel plating on aluminum alloy under the middle temperature of 70 ℃, an activator (fluoride) was added and the main complexing agent was adjusted in the chemical bath. Appropriate concentration of activator can accelerate the electroless nickel plating and improve the comprehensive performance of coatings. When citric acid was replaced by aminoacetic acid as the main complex agent, the corrosion resistance of coating was obviously improved. The corrosion potential increased, the corrosion current decreased and the resistance of color degeneration was also obviously enhanced. The Ni-P coatings with good comprehensive performance were produced in the bath containing 2 g·dm-3 KF and 8 g·dm-3 aminoacetic acids.