Disclosed herein is a method of preparing a nanoporous organic-inorganic hybrid film. The method includes preparing an organic sol including a compound having amino groups, a compound having isocyanate groups, and a solvent; adding an inorganic oxide precursor to the organic sol to form a mixed solution; and subjecting the mixed solution to heat treatment to form an organic molecule network structure in which the organic sol is gelled, and an inorganic molecule network structure located along a surface of the organic molecule network structure.