A superhydrophobic surface was fabricated via a non-induced phase separation method by combination of two polymers (polyvinylidene fluoride and polydimethylsiloxane) enhanced with cellulose nanocrystals (CNCs). The aggregation of the polymers and particle sizes were both effectively reduced during the phase separation owing to the electrostatic repulsion between CNCs and their high surface area, which led to a construction of a fine and uniform micro - and nano-structures on the surface of the substrates, correspondingly endowed them a stable superhydrophobicity. The morphology and structure of the CNCs and superhydrophobic surfaces were characterized by FTIR, SEM, AFM, contact angle measuring instrument and 3D optical profilometer. It was found that the surface of the substrates had uniform micro-nano rough structure. The water contact angle was up to 158°, and the lowest rolling angle is 2°, indicating obvious superhydrophobic characteristics. After mechanical friction (over 500 times), acid-base treatment (pH 1 ~ 13), temperature change (-40 ~ 40°C) and ultraviolet irradiation (0 ~ 320 h), the superhydrophobicity of the substrate surface was not reduced obviously. In addition, the substrates had excellent self-cleaning and oil-water separation efficiency. The maximum separation efficiency of the super hydrophobic cotton cloth was up to 98.4%.