Before the preparation of antifreeze, check and determine the antifreeze components of the effective components, water and content of incompatible. When preparing antifreeze whether stir evenly, whether crystallization and precipitation phenomenon. Compound agent solution whether there is the existence of suspended solids, powder directly added to the antifreeze, whether there is no broken moisture caking. When various admixtures exist at the same time, the order of addition should meet the requirements.