In the pouring process of the casting of machine tool bed, the principle of high temperature and low temperature pouring should be followed. Because increasing the temperature of the molten metal is conducive to the complete melting of inclusions, melting slag floating, easy to clear slag and degassing, reduce slag and gas hole defects in machine tool castings, lower pouring temperature, it is advantageous to reduce the gas solubility in molten metal, liquid shrinkage and high-temperature metal liquid on the surface of the cavity baking, to avoid the formation of pores, Sticky sand and shrinkage and other defects. Therefore, in the premise of ensuring full mold cavity, the lower pouring temperature is used as far as possible. The process of injecting molten metal from the pouring ladle into the mold is called pouring. Improper pouring operation will cause the casting defects of the machine tools such as insufficient pouring, cold insulation, blowhole, shrinkage and slag, and cause personal injury.