The invention discloses modularized ecological filter filling for removing water body pollutants and a preparation method of the modularized ecological filter filling. The modularized ecological filter filling is prepared from a water-permeable filling module and a perforated shock tube arranged in the water-permeable filling module; the preparation method of the modularized ecological filter filling comprises the following steps: uniformly mixing raw materials including composted sludge, phosphorous slag, blast-furnace slag, cement and quartz sand with water to form slurry; putting the slurry into a mold; vibrating and molding; inserting the perforated shock tube; de-molding and curing to obtain a product. The modularized ecological filter filling has the advantages of high mechanical strength, easiness of forming a film, good water permeability and easiness of backwashing and regeneration; a water purification effect is good, the filling is convenient to fill and the utilization cost is low.