The filter is an anti-corrosion device used for removing little solid particles in the liquid, which can protect the normal operation of compressor, pump, meter and other equipments. When the liquid enters the filtering cartridge with a certain filtering net, block the impurities and discharge the clean filtered liquid via the outlet of the filter, when the cleaning is required by just removing the demountable filtering cartridge, and re-assembling after handling, contributing to a very convenient operation and maintenance, nowadays, it is widely applied in the fields involving petroleum, chemical industry, pharmacy, refrigeration, light industry and environmental protection. When it is connected in series at the entry of pump or the other parts in the pipeline system, it can prolong the service life of the pump and other equipments, and ensure the safety of the whole system, so the basket filter is the essential device applied for industrial production that enables the machinery and equipments (including compressor, pump) and meters to be normal operated or run so as to stabilize the technological chain and guarantee the safe production process.