The effects of microstructure evolution on the strength and hardness of 7050 aluminum alloy during the process of two-stage aging were systematically studied in this paper. The results showed that a double-peak phenomenon occurred in the double-stage aging of 7050 aluminum alloy. Both the hardness and strength of the second aging peak were slightly higher than those of the first peak. Transmission electron microscopy (TEM) observations indicated that the increase of the hardness and strength for the second aging peak was caused by an increase in the number of h￠ phases. Additionally, the synergistic effect of h￠ phase and GP zones was better than the effect of GP zones on its own.