A two-step solution immersion method was used to successfully fabricate a superhydrophobic film on the surface of the core, which can effectively separate oil and water. The optimal reagent concentration of the superhydrophobic surface was 1.0 wt % aminopropyl triethoxysilane + 0.7 wt % stearoyl chloride + 0.2 wt % triethylamine, suitable for reservoirs with a formation temperature around 40-100 degrees C, and the maximum contact angle of the prepared superhydrophobic surface was 155 degrees with a sliding angle smaller than 3 degrees. A scanning electron microscope and a contact angle measuring instrument were used to characterize the surface. Displacement experiments and oil-water separation experiments demonstrated that the superhydrophobic surface could significantly change the wettability of the formation and have a good selective water shut-off performance. The presented method is rapid and convenient and thus should be of significant value for the industrial fabrication of the superhydrophobic surface and should have a promising future in selective water shut-off in oilfields.