Oily and saline wastewater is a significant waste stream generated in association with oil and gas production, the direct discharge of which will pollute the environment and impair people's health. Conventional polymer membranes suffer from low flux and serious fouling when used for treating oily and saline wastewater. Reported herein is the fabrication of a novel reverse osmosis membrane (PAMAM/TMC RO membrane) prepared with Ethylenediamine cored poly(amidoamine)(PAMAM) dendrimer and trimesoyl chloride(TMC) by interfacial polymerization on the PSf ultrafiltration membrane. A smooth and hydrophilic skin layer was constructed on the substrate PSf membrane and endows the composite membrane with an antifouling performance. In separation of the stable oily and saline water emulsion with an oil droplet size about 300nm, the rejection of oil droplet and NaCl was about 99% and 89.3% respectively, and the water flux was about 18.39 L/(m2•h). After running for 24h, the flux only decreased about 3%, the rejection rate of oil and salt maintain 98% and 88%, exhibiting an excellent ability to resist oil pollution. Further investigation demonstrated its outstanding performance to resist chlorine, acid and alkali environment. Finally, it is believed that such membrane has great potential for practical applications.