Precision casting is a steel made of steel. When the strength of the casting is higher, the cast steel should be adopted when the cast iron is not met. However, the steel water is less liquid than the cast iron, so the thickness of the pouring structure is not too small, and the shape should not be too complex. It can improve the liquidity of steel water when controlling the amount of silicon in the upper limit. The casting steel shall be divided into general works with cast steel and welding structure with cast steel, stainless steel cast steel and heat resistant steel cast steel.