To promote the application of water evaporation inhibitors to plain reservoirs in southern Xinjiang, we prepared a water evaporation inhibitor system with octadecanol and short-chain alcohol n-butanol molecular membrane substrate by ultrasonic dispersion technology. We also discussed the factors influencing the performances of emulsion inhibitor, such as mix proportion, temperature, surface concentration, and duration. Results show that the inhibition rate of octadecanol and n-butyl alcohol heterogeneous latex system is higher than those of other groups. Inhibitors can be used for up to 180 hours in the test cell. Moreover, the performance of emulsion inhibitor is very stable, and the system has strong resistance to temperature and impurity interference. Therefore, the system can be applied to the natural environment subject to dust with high temperature difference.