Abstract: Provided are a high temperature-resistant composite nanofiltration membrane and a preparation method thereof. The high temperature-resistant composite nanofiltration membrane includes a base membrane and a polyamide membrane arranged on the base membrane; wherein the polyamide membrane is prepared from raw materials comprising: an amine, an inorganic salt, a silane additive, a polyacyl chloride, and an oil phase solvent; and the silane additive is at least one selected from the group consisting of 3-aminopropyltriethoxysilane, divinyltriaminopropyltrimethoxysilane, N-cyclohexyl-?-aminopropyltrimethoxysilane, and trimethoxy[3-(phenylamino)propyl]silane.

Abstract: The present disclosure provides a preparation method of a reverse osmosis composite membrane, including the following steps: coating a gelatin solution on a non-woven fabric layer and cooling to form a gelatin gel layer; coating a salt solution on a surface of the gelatin gel layer to obtain a gel/non-woven fabric composite membrane; placing the gel/non-woven fabric composite membrane in an aqueous phase solution, transferring into an oil phase solution, and conducting interfacial polymerization to obtain a non-woven fabric/gel/polyamide composite membrane; placing the non-woven fabric/gel/polyamide composite membrane in water, and heating to remove the gelatin gel layer to obtain a non-woven fabric/polyamide composite membrane; and introducing a trimesoyl chloride (TMC) gas from a side where the non-woven fabric layer is away from a polyamide layer in the non-woven fabric/polyamide composite membrane, conducting gas-liquid interfacial polymerization by chemical vapor deposition (CVD), and drying to obtain th