Method for preparing large-area orderly porous membrane

The invention discloses a method for preparing a large-area orderly porous membrane. The method comprises the following steps: (1) dissolving a polymer and a surfactant into a solvent so as to prepare a polymer solution; (2) dropwise adding the prepared polymer solution to the surface of a substrate, and putting the substrate into a closed container; (3) introducing steam into the closed container from the downside of the substrate, controlling relative humidity to a stable state, and carrying out standing on the substrate for a certain time in a stable-state humidity atmosphere; (4) taking the substrate out of the humidity atmosphere, and drying the substrate, thereby obtaining the orderly porous membrane. According to the method, the preparation of nanoscale-pore-size and micron-scale-pore-size porous membranes can be taken into account by one process route, and the process route is not required to be changed during the production of the porous membranes of different pore sizes, so that the production cost