The invention discloses a method for preparing a super-hydrophobic coating with a nanocrystalline cellulose/silicon dioxide (NCC/SiO2) composite template process. The method comprises the following steps: (1) treating microcrystalline cellulose (MCC) with 56% sulfuric acid; (2) performing centrifugal washing; (3) replacing water in an NCC suspension solution with ethanol; (4) grinding for later use; and (5) freezing a sample to subzero 30 DEG C and performing vacuum freeze-drying. The method has the advantages that stearic acid is taken as a modifier and can produce a dehydration reaction with surface -OH of SiO2/NCC, and stearic acid further introduces hydrophobic -CH3 groups, so that the surface energy of SiO2/NCC is reduced; and an NCC and SiO2 compound has not only the properties of a biopolymer material but also the properties of an inorganic material such as weather resistance, hardness and the like, can be used for modifying indoor and outdoor coatings, and can play a role in aspects of building floor cleaning, furniture pollution prevention and the like.