Vapor-liquid equilibrium (VLE) data are measured and reported for the LiCl + CaCl2 + H2O system. The experimental procedures were carried out with pressures between 6 and 101.3 kPa in a computer-controlled glass apparatus. We obtained the relationship between solubility of salt and vapor pressure by analyzing and summarizing the results. Then, a modified NRTL model based on the hypothesis of hydration was used in this paper. By correlation of literature and experimental data for LiCl + H2O, CaCl2 + H2O, and LiCl + CaCl2 + H2O (pressure spanning from 5 to 101.3 kPa), some parameters were modified for improving the accuracy of the calculation. Meanwhile, the model was successfully applied to predict the VLE data in LiCl + CaCl2 + H2O systems with the modified binary parameters.