Dry milling has requirements for water content of material (usually <4%). Materials with high water content need to be properly dried before milling or reduce the moisture content to a certain limit before milling. The powder products involved in food, medicine, fertilizer, pesticide and other industries will inevitably appear agglomeration during transportation and storage, which affects the normal use of these products and the full play of their beneficial effects. Before milling or powder surface modification, powders need to finish depolymerization.