7075 Al-alloy plates of 6 mm in thickness were subjected to shot peening treatments with varying parameters. Then the effect of shot peening on the microstructure, surface-roughness and -hardness as well as corrosion performance was assessed, aiming in optimization of the shot pinning processes. The results indicated that shot peening led to grain refinement and work hardening of the shot peened surface. Both the roughness and hardness increased with the increase of the ball diameter and the injection pressure. As the repetition rate of shot peening area increased from 100% to 300%, the hardness increased, while the roughness rose firstly and then decreased. When the ball diameter was 0.1 mm and the injection pressure was 0.3 MPa, the hardness reached 220.7 HV with the repetition rate of 300%, while the roughness reached a minimum value of 0.623 μm with the repetition rate of 200%. In comparison with the single shot peening, the double shot peening may result in significant reduction in surface roughness from 4.131 μm to 2.232 μm, but in slight increment in hardness from 223 HV to 227 HV. Besides, the corrosion potential increased from -0.7276 V for the alloy before shot pinning to -0.6816 V for the alloy after twice shot pinning, indicating that the double peening can significantly enhance the corrosion resistance of the 7075 Al-alloy.