By using the universal mechanical testing machine and SEM, the influence of quenching parameters on the mechanical properties of 7075 aluminum alloy has been studied, and the optimal quenching parameters have been got. The experimental results show that the temperature range of the quenching treatment is too wide. However, the over-burning will occur when the temperature is above 490°C. So the optimal quenching temperature is from 465°C to 475°C. The water temperature and the transfer time are below 40°C and 30s, respectively. The time interval between the quenching and aging treatment is found to have little influence on the mechanical properties of 7075 aluminum alloys.