The isothermal vapor-liquid equilibrium data for dimethyl ether-methanol-water ternary system were measured at 333.15 K，353.15 K

373.15 K and 393.15 K in a self-sucking type agitated static equilibrium cell.The effect of pressure and temperature on vapor-liquid equilibrium of dimethyl ether-methanol-water ternary system was analysed

the contents of dimethyl ether in vapor phase and liquid phase increased with increasing pressure

but decreased with increasing temperature.Thermodynamic calculation of vapor-liquid equilibrium data of dimethyl ether-methanol-water ternary system was carried out by using the method based on equation of state-activity coefficient

with PR equation for fugacity coefficients of vapor phase and NRTL equation for activity coefficients of liquid phase

and the calculated data were in agreement with the experiment data.