The fineness of mud will affect the size of mud blank. The fineness of slurry is an important factor affecting the fluidity of slurry, shrinkage of products, high temperature liquid content and water absorption of products, which will affect the suspension, air permeability and flexural strength of green bodies. The fineness of slurry required for grouting molding is strict. If the slurry is too fine, the slurry eating time will be prolonged, and the green body will collapse easily after grouting; Mud particles are too coarse, which leads to many semi-finished products being damaged, low flexural strength and poor processability.