To find the best experimental scheme and technological conditions for hydrophobic modification of potato starch. The experiment utilized oxidation, cross-linking and esterification methods for hydrophobic modification of potato starch. Orthogonal design assistant (II) 3.1 was used to screen the optimal combination of experimental conditions and the cross-linking method was found to be the best method after analyzing the water absorption and viscosity performance. SPSS13.0 was used to further analyze study the data coming from cross-linking experiments through single factor and variance analysis. After cross-linking modification, the water absorption rate of potato starch was decreased by 43.44%, and the viscosity in liquid paraffin was reduced by 70.54% . After overall consideration of water adsorption, viscosity and practical feasibility, the optimal process condition was determined to be: water bath temperature 55 ℃, pH 11, quality ratio of epoxy-chloropropane to dry basis of starch 1.5∶100. Under this process condition, the water absorption of the modified starch was 20.96%, and the viscosity was 156 mPa·s. The best method for hydrophobic modification of potato starch was the cross-linking method. The optimal process condition was obtained, which provided reference for the research on improving the hydrophobicity of starch.