Research on heat treatment process of 6016 aluminum alloy has been carried out by means of hardness measurement，mechanical properties test and bake- hardening property test. The results indicate that hardness of alloy increases with the rise of solution temperature and solution time increase. The hardness of alloy initially decreases and then increases with pre- aging time increase when pre- aging. The higher the temperature of pre- aging，the bigger the decrease value of hardness will be. The heat treatment process of 6016 alloy satisfying the demand of outer panel property is：540 ℃×20 min solution treatment + 120 ℃×10 min preaging.