▎ 摘　　要

NOVELTY - A gas separating film comprises porous substrate adhered to the composite film, where the film further comprises mixture of graphene oxide and polymer-supported polyethyleneimine solution. USE - Gas separating film. ADVANTAGE - The film has excellent gas separation performance and wide application range, and can be prepared in a simple manner. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for preparing gas separating film, which involves preparing graphene dispersion liquid and polymer-supported polyethyleneimine solution, cleaning porous substrate, coating the substrate with polymer-supported polyethyleneimine solution, drying the substrate in air, coating the substrate with graphene dispersion liquid, followed by drying, heating and curing to obtain finished product.