High-pressure oil filter element is installed in the oil circuit of the hydraulic system to remove metal powder and other mechanical impurities worn by various components in the hydraulic system to keep the oil circuit clean and prolong the life of the hydraulic system; the low-pressure series filter element also has a There is a bypass valve. When the filter element is not replaced in time, the bypass valve can be opened automatically to ensure the normal operation of the system. At present, the industry series products are substitutes for similar products in the United States, Germany, Britain and other countries.