Bag filter is a kind of multi-purpose filtration equipment with novel structure, small volume, simple and flexible operation, energy saving, high efficiency, airtight work and strong applicability. Bag filter is a new filtration system. The filter bag is supported by a metal basket inside the filter. The liquid flows in from the inlet and flows out from the outlet after being filtered by the filter bag. The impurities are intercepted in the filter bag. After the filter bag is replaced, it can continue to be used.