Abstract: The most common hydraulic parts in the production of grinder, such as disc cover, flat plate, square and short cylinder, have simple shape and structure, but they have large section thickness, high technical requirements and high foundry reject rate（30%～40%）.The centrifugal slag-collecting ladle is used in the production of platecover hydraulic parts to solve the problems of slag removal and feeding;In the production of plate hydraulic parts,the process of“Horizontal casting and vertical casting” is adopted to meet the high quality requirements of the two major planes of the castings;In the production of square and short cylindrical hydraulic parts, the technology of“One billet and many pieces continuous casting” and“Horizontal casting and vertical casting” are adopted,and through proper composition selection and control, it ensures the yield and process yield of thick and large section hydraulic casting. The concept of modulus is introduced, and the modulus of each geometry is calculated and compared, which provides a basis for accurately controlling the cooling rate of castings.