Octan-2-one is a promising extraction solvent with low solubility in water. The experimental solubility behavior of benzene-1,2-diol, benzene-1,3-diol, or benzene-1,4-diol in mixtures of octan-2-one + water were measured at 298.2 K, 318.2 K, and 338.2 K and ambient pressure. The distribution ratio and selectivity for these three isomers of dihydroxybenzenes were calculated from the experimental tie-line data to evaluate the extraction efficiency of octan-2-one. Compared with other ketones, octan-2-one has almost the best selectivity to extract dihydric phenols from water. The Hand and Othmer-Tobias equations were applied to test the reliability of the experimental liquid-liquid equilibrium (LLE) data. The LLE data for the systems were correlated by the nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) thermodynamics models, and the results showed that both models correlated the LLE data well for these ternary systems. The accuracy of NRTL regression measured data is higher than that of UNIQUAC model. The sigma-profile reflects the polarization effect of the molecule surface. The feasibility of octan-2-one extraction of benzenediol was analyzed by the interaction of each component reflected by the sigma-profile.