The invention relates to a preparation method of a superhydrophobic nanomaterial. The preparation method comprises steps as follows: firstly, nano silica is ultrasonically dispersed in a part of an absolute ethyl alcohol solution, then, a silane coupling agent is added to a mixed solution to be rapidly stirred for 2 h (at the water bath temperature of 60 DEG C), the mixture is aged at the room temperature for 24 h, and a solution A is obtained; secondly, the silane coupling agent is added to the remaining absolute ethyl alcohol solution to be rapidly stirred for 2 h, fumed silica is added, andthe mixture is continuously stirred for 30 min, finally, perfluorinated silane is slowly dropwise added, the mixture is stirred intensely for 5 h, and a solution B is obtained; finally, the solutionA and the solution B are mixed and stirred for 2 h, a film-forming agent is added, the mixture is continuously stirred for 2 h, and the superhydrophobic nanomaterial is obtained. The preparation method has the advantages as follows: the superhydrophobic nanomaterial has stable and durable superhydrophobic performance, is non-corrosive, free from environmental pollution, low in cost and wide in application range and adopts a simple process.