The invention provides a hydrodynamic backwash filter screen filter which comprises an electromagnetic reset mechanism, a water wheel drive mechanism, a blowdown assembly, a water inlet cavity, an intermediate cavity, a filter cavity and a controller, wherein the blowdown assembly comprises a blowdown pipe, a seal cover and a sewage inlet; the water wheel drive mechanism comprises a water wheel, a water wheel housing, an outlet, a water wheel water inlet pipe and a nozzle; the electromagnetic reset mechanism comprises an armature, an electromagnet, a spring, a limiting block and a touch force sensor; the water inlet cavity is a hollow cylinder; the water inlet cavity is connected with the water inlet pipe; a water inlet pressure sensor is arranged on the water inlet pipe; the intermediate cavity is of a hollow plum column structure; the hollow cylinder is arranged at the center of the intermediate cavity; the inner wall of the center cylinder and the outer wall of the blowdown pipe are in tight contact; a circular tube-like connection channel corresponding to an opening is formed in the periphery of the circumference of the hollow cylinder; and the filter cavity comprises a filter housing and a filter core. The hydrodynamic backwash filter screen filter is simple in structure and high in washing efficiency and is driven by hydraulic power; and periodical fluctuation backwash is adopted.