The invention discloses an acid, alkali and organic solvent resisting diaphragm material, and a preparation method and an application thereof. The diaphragm material is prepared from hydrophilic and hydrophobic block copolymers, and has a nano-pore structure. The nano-pore structure in the diaphragm material is prepared through an inorganic filler structure preparation method or an immersion phase separation method. The acid, alkali and organic solvent resisting diaphragm material has polar hydrophilic groups, and the surface of a diaphragm can be further grafted with other organic molecules with permselective functional groups by using above active groups, so realization of diaphragm functionalization is facilitated to meet various separation requirements. The diaphragm material can be applied in cation separating systems, such as separation of ions of lithium, copper, gold, platinum, palladium, silver, boron, rubidium, cesium, antimony, bismuth, nickel, mercury and other metals.