Aluminum has a wide range of uses in the automobile market，because of its simple process, rich material sources and low cost. With the development of automobile market and the worsening of air pollution, the promotion of the light -weight automobiles continues to increase. The development of lightweight materials such as aluminum-magnesium alloy is promising. Data shows that the total proportion of aluminum-magnesium alloy die-casting increased steadily to 13.4% in 2015. The benefit from the lightweight car, aluminum demand is expected to continue to increase in the future.