The invention relates to a slope protection forming method of a landscape-type multi-level stepped constructed wetland, which has the effect of intercepting and purifying pollutants entering river channels in the form of surface sources. Sand-free concrete piles and slabs are inserted to form pile-slab components, and a slope protection system from high to low is formed on the river bank slope from the bank slope to the river bed. Planting areas are set on the side of the pile slabs, and there are fillers inside. Geotextiles are installed on the bankside side of the slab, so that when the non-point source pollutants flow from the river bank to the river, the plants planted in the planting area absorb the eutrophication in the polluted water, and the biofilm is formed on the surface of the filler to absorb and degrade the pollutants. After this The sewage treated at the first stage continues to infiltrate or overflow, enters the second row, and goes down step by step. Finally, the sewage is purified to a greater extent and flows into the river. It solves the defects of natural, hard and ecological slope protection. The structure is simple, easy for industrial production, the construction amount is small, the land is saved, and the landscape is beautified.