The paper presents theoretical studies of absorption gas mixture separation under ultrasonic vibrations influence, which provides cavitation and acoustic process intensification. The theoretical studies based on consecutive consideration of this process beginning with single cavitation bubble dynamic which generates shockwave for increasing interface “ gas-liquid” and ending with determining absorption productivity providing required concentration of target gas mixture component. In result of the studies, it is evaluated, that cavitation and acoustic intensification increase interface “ gas-liquid” up to 3 times with amplitude of oscillations of solid surface 1… 2 μ m. From the data about surface increasing the analysis of the gas absorption process in the liquid film was performed. For this analysis, the model of gas absorption taking into account surface increasing under acoustic cavitation influence was developed. The model of absorption allows to obtain that the absorption productivity under ultrasonic vibrations influence is increased up to 2 times and more. The obtained results can be used for development of high-efficiency absorption apparatus that is supplemented by ultrasonic influence sources.