The disclosure provides a method to optimize atomic layer deposition comprising the following steps: (A) providing a cellulose nanofiber; (B) acidifying the cellulose nanofiber by an acidifying treatment agent; (C) hydrophobing the acidified cellulose nanofiber by a hydrophobinghydrophobic treatment agent; (D) dissolving the acidified and hydrophobed cellulose nanofiber in a solvent to form a cellulose nanofiber solution; (E) coating the cellulose nanofiber solution on a silicone resin film; (F) heating the coated silicone resin film to form a cellulose nanofiber layer on a surface of the silicone resin film; and (G) forming an inorganic coating layer on the surface of the silicone resin film having the cellulose nanofiber layer by atomic layer deposition.