Double-filter-element continuous alternate back-flushing cleaning water quality filter

The invention relates to a double-filter-element continuous alternate backwashing water quality filter, which comprises a filter element device, filter element device filter elements, an element pipe, a filter element device water outlet pipe, a filter element device water inlet pipe, a filter element device lower cone, a connecting water pipe, a check valve, a constant-pressure water tank, a water tank water outlet pipe, a filter element device electromagnetic valve, a blow-off pipe, a tangent water inlet pipe and a filter element device upper seat, the filter is characterized in that the filter element is made into a circle by stainless steel or plastic, and the lower part of the filter element is a cone; the filter element device is tightly pressed in a rubber pad groove of the filter element device upper seat; an external thread is turned at the upper end of a core pipe; an inner threaded hole of the filter element device upper seat is screwed with an outer thread of the element pipe, an outlet end of a l