▎ 摘　　要

NOVELTY - Composite film comprises polyether sulfone, graphene oxide and silane coupling agent KH570. USE - Composite film used for processing seawater, desalinating brackish water and purifying water. ADVANTAGE - The composite film is prepared in simple manner, and has high performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing composite film, which involves: (A) adding dimethylformamide is added into graphene oxide and then treating by ultrasonic wave for 2 hours to obtain solution; (B) adding polyvinylpyrrolidone into solution and then cooling to obtain mixture; (C) washing mixture with deionized water and then drying it; and (D) adding ethanol and silane coupling agent KH570 and then stirring by magnetic stirrer to obtain the product.