▎ 摘　　要

NOVELTY - The preparation method of a composite film based on electro-gradient morphology regulation involves: providing a porous conductive substrate; providing an electrolyte solution, and immersing the conductive substrate in the electrolyte solution; applying a positive potential on the conductive substrate and initiating an electropolymerization reaction to enable a polymer to grow in situ on the surface of the substrate to obtain an electropolymerized substrate film; providing a graphene oxide doped electrolyte solution, and immersing the electropolymerized base film in the graphene oxide doped electrolyte solution; and applying a positive potential to the electropolymerization base film to initiate electropolymerization reaction, so that the graphene oxide doped polymer grows in situ on the surface of the electropolymerization base film, and the composite film with adjustable step structure and chemical composition is obtained. USE - Preparation method of a composite film used in membrane water treatment such as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis. ADVANTAGE - The prepared composite film by the invention has the characteristics of controllable surface appearance, hydrophilicity and hydrophobicity and controllable chemical composition, and has good application prospect in the field of membrane water treatment. DESCRIPTION OF DRAWING(S) - The drawing shows a flow chart of a method for preparing the composite film. (Drawing includes non-English language text). Selection and pretreatment of porous conductive substrate (S100) Preparation of electrochemical polyelectrolyte solution (S200) Preparation of electropolymerized basement membrane with nanostructure (S300) Preparation of graphene oxide doped electrolyte solution (S400) Preparation of electrogenerated gradient morphology regulation composite membrane (S500)