Composite polyamide nanofiltration membrane and preparation method thereof

The invention discloses a composite polyamide nanofiltration membrane and a preparation method thereof, the composite polyamide nanofiltration membrane comprises a base membrane, a polyamide desalination layer and a temperature-sensitive layer, the polyamide desalination layer is formed on at least part of the surface of the base membrane, and the polyamide desalination layer comprises polyamide; the polyamide desalination layer is formed on the base membrane, the temperature-sensitive layer is formed on at least part of the surface of one side, far away from the base membrane, of the polyamide desalination layer, the temperature-sensitive layer comprises polyisopropylacrylamide, at least part of the polyisopropylacrylamide is grafted to polyamide, and the grafting degree of the polyisopropylacrylamide on the polyamide is 0.5%-1%. The temperature-sensitive layer on the composite polyamide nanofiltration membrane has a high-temperature self-protection function on an internal polyamide desalination layer struct