NOVELTY - Constructed wetland sewage treatment based on modularized internal interstitial filler, comprises (a) preparing a mold with two built-in through holes, mixing and stirring the coarse aggregate, fly ash, cement, naphthalene superplasticizer and water, pouring in the mold, molding to obtain a modularized internal interstitial artificial filler; and (b) placing the artificial filler, removing mold, covering the molded filler by a plastic film, spraying small amount of water on the surface for maintaining 90 % of humidity, naturally curing, and placing in constructed wetland processing system.    USE - The method is useful for constructed wetland sewage treatment based on modularized internal interstitial filler.    ADVANTAGE - The method utilizes the power plant waste fly ash as the material of the constructed wetland filler; combines gravel, cement and naphthalene superplasticizer to meet the requirements of strength, porosity and ecological safety; optimizes the proportion of the filler materials and the structural configuration of the constructed wetland filler; constructs the combined filler-wetland plant-wetland microorganism trinity in the wetland processing system with the constructed wetland plant and microorganisms; achieves cyclic utilization of the waste resource; and is suitable for the constructed wetland sewage treatment and the recovery of landscape water.    DETAILED DESCRIPTION - Constructed wetland sewage treatment based on modularized internal interstitial filler, comprises (a) preparing a mold with two built-in through holes, mixing and stirring the coarse aggregate, fly ash, cement, naphthalene superplasticizer and water, pouring in the mold, and molding to obtain a modularized internal interstitial artificial filler; and (b) placing the artificial filler at 15-25 degrees C for one day and night, removing the mold, covering the molded filler by a plastic film, spraying small amount of water on the surface every 24 hours for maintaining 90 % of humidity, naturally curing for 28 days, and placing in an constructed wetland processing system, where in the step (a), the mass ratio of coarse aggregate, cement, fly ash, and water is 1: (0.15-0.20):(0.05-0.1):(0.06-0.08), and naphthalene superplasticizer is added according to 1-2 % of the total mass of the cement and fly ash.