Reverse osmosis membrane substrate is made of polyester fiber by wet process. The product has good smoothness, good breathability, good flatness and high tensile strength. The product is mainly used as a non-woven layer in the three-layer structure of reverse osmosis membrane. Combined with polysulfone layer and desalting layer, its chemical properties and structural materials can reduce the COD and total solution amount of landfill leachate wastewater, and can also be used for concentration of high concentration substances.