During the process of oxidizing cyclohexene to produce 1,2-epoxycyclohexane by hydrogen peroxide, many byproducts have generated. In order to get 1,2-epoxycyclohexane of high purity,the vapor-liquid equilibrium (VLE) data of cyclohexene(1)-1,2-epoxycyclohexane(2)-cyclohexanol(3) ternary system were studied at 101.33 kPa by an improved EC-2 VLE still. The VLE data were predicted by Wilson equation. Based on Wilson equation consort parameters which were obtained by fitting the VLE experiment data of three corresponding binary system, the VLE experiment data were correlated by Wilson equation, using the error sum squares of vapor composition as the objective function. Variations between the values from the predictive value, theoretical calculation and the experimental data are very minor, which indicated that the experiment data are suitable for the engineering design．
