Preparation method of composite membrane and device for preparing composite membrane

The invention discloses a preparation method of a composite membrane and a device for preparing the composite membrane. The preparation method of the composite film comprises the following steps: carrying out first pretreatment and first coating treatment on the opposite surfaces of a composite base film formed by laminating more than two layers of base films to respectively form metal film layers; and performing layer-by-layer separation treatment on the base films, performing second pretreatment and first coating treatment on the surfaces of the newly exposed base films, and forming metal film layers on the surfaces of the newly exposed base films respectively. The device for preparing the composite membrane comprises a pretreatment unit, a coating unit and a base membrane separation unit. According to the preparation method of the composite film provided by the embodiment of the invention, the metal film layer can be formed on the surface of the lower base film to form the composite film, and high yield and production efficiency of the composite film are ensured. The device for preparing the composite membrane can effectively implement the preparation method of the composite membrane.