Filler according to the principle of filling can be divided into atmospheric filling machine, pressure filling machine, liquid filling machine, oil filling machine, paste filling machine, paste type filling machine, granular slurry filling machine, powder filler, large bucket water filler and vacuum filling machine. The pressure filling machine is filled by the liquid weight under atmospheric pressure. This type of filling machine is divided into regular filling and fixed volume filling two kinds, only suitable for filling low viscosity gas-free liquids such as milk, liquor, mineral water and so on.