The separation membraneMembranes of lithiumLithium and magnesium was important for the development of lithiumLithium resources. At present, nanosheets commonly used for membraneMembranes such as graphene oxideGraphene oxide are costly and difficult of exfoliation. Although montmorillonite mineral nanosheets are inexpensive, they often have smaller lateral dimension. Vermiculite, an equally inexpensive layered silicate, has weaker van der Waals between its molecular layers, which facilitates the production of larger-lateral-dimension nanosheets to improve separation ability. In the experiment, we obtained single-layer vermiculite nanosheetsVermiculite nanosheets with a lateral diameter of nearly micrometers through ion intercalation and ultrasound. When forming a membraneMembranes through vacuum filtration, glutaraldehyde was added to bond the nanosheets at a specific distance, resulting in a self-supporting vermiculite nanosheetVermiculite nanosheets with a high lithiumLithium and magnesium separation coefficient (9.47). We hope that this exploratory work can provide some reference for the selection of raw materials for lithiumLithium and magnesiumSelf-supporting membrane separation membranesMembranes.