The cooling effect of the mold directly affects the quality and production efficiency of the product, such as poor cooling, large shrinkage of the product, or uneven shrinkage and deformation of the warped surface. On the other hand, the whole or part of the mold is overheated, so that the mold cannot be formed normally and production is stopped. The design and processing of the cooling system depends on the shape of the product. Do not omit this system because the mold structure is complex or difficult to process. Especially for large and medium-sized molds, the cooling problem must be fully considered.