Hydrophobic emulsion was synthesized by copolymerization of butyl acrylate and vinyl silicone resin. α-Fe2O3 nanoparticles were prepared by precipitation method, and then modified by the silane coupling agent. Superhydrophobic cotton fabric was prepared by dip-coating of cotton fabric with hydrophobic emulsion and α-Fe2O3 dispersion. The structure and morphology of α-Fe2O3 and superhydrophobic cotton fabric were characterized by XRD, FTIR and SEM. The influence of the dip-coating times of emulsion and α-Fe2O3 dispersing on the hydrophobicity of cotton fabric was investigated. And the influence of UV irradiation on the wettability of superhydrophobic cotton fabric was studied. Moreover, oil-water separation performance of the superhydrophobic cotton fabric was determined. The results showed that the cotton fabric obtained superhydrophobicity after 2 times dip-coating of hydrophobic emulsion and α-Fe2O3 dispersion respectively, and its contact angle was 158.6?. After UV irradiation, the front side of the fabric turned to be superhydrophilic, while the reverse side was still superhydrophobic, the resulting cotton fabric showed unidirectional moisture conductivity. The separation efficiency of superhydrophobic cotton fabric to oil and water in oil-water mixture was 96.1% and 99.0%, respectively.