Precision casting casting process is a complex, in the process of production, precision casting of annealing process on the improvement of mechanical properties and stability of the precision casting size has a very important influence.Precision casting annealing treatment is aluminum alloy castings can be heated to high temperatures, the temperature of heat preservation after a period of time, and then with the furnace cooling process is called annealing.Annealing process can eliminate the internal stress of castings can be stable casting size, also can ensure less and deformation of the casting.This can increase the plasticity of casting.This is very important for the casting process.Without this process, the casting can't get good also not very good to improve work efficiency.