The utility model provides an irrigating filtering system. The irrigating filtering system comprises a water inlet pipe, filters, a water outlet pipe, blowdown valves and a blowdown pipe, wherein the water inlets of the blowdown valves are communicated with the water outlets of the water inlet pipe; the blowdown openings of the blowdown valves are communicated with the blowdown pipe; the water outlets of the blowdown valves are communicated with water inlets of the filters; the water inlets and the water outlets of the blowdown valves are horizontally arranged; the water outlets of the filters are communicated with the water inlets of the water outlet pipe. The blowdown valves are additionally arranged at the water inlets of the filters, so that primary blowdown treatment is performed on the water, so that the impurity content of the water entering the filters is lowered, the treatment quantities of the filters are effectively reduced, the treatment efficiency of the filters is improved, and the service lives of the filters are prolonged; furthermore, precipitation valves are also additionally arranged after the blowdown valves are additionally arranged, so that further impurity removing treatment is performed on the water, so that the treatment quantities of the filters are reduced better, the treatment efficiency of the filters is further improved, the service lives of the filters are further prolonged, and the replacement cycles of the filters are prolonged.