Theoretical analysis of the adiabatical evaporation process from the free surface of a continuous falling liquid cylindrical column was carried out. The axial distribution of temperature on the vpaor-liquid interface and evaporation flux were obtained numerically. It was shown that the rate of this non-equilibrium surface evaporation accountes for only 20% of the theoretical maximum calculated under thermodynamic equilibrium. The evaporation rate is controlled by heat transfer from the inner of the liquid cylindrical column. The evaporation rate attenuates rapidly along the flow direction. When x/L=0.5, the evaporation progress ηx is only around 0.25, which means that the evaporation is coming to the end. It revealed that the refreshment on the surface of liquid is the key to intensify the surface evaporation process. The simulation results of this model were verified by the experimental data of the adiabatic vacuum evaporation from the free surface of a continuous falling liquid cylindrical column, with an error within 10%.
