The invention relates to a process for recovering butanone by a pervaporation method. The process specifically comprises the following steps of: pressing hydrous butanone solution in a preheater and an evaporator through a pump so that the hydrous butanone solution goes into a pervaporation membrane separation unit in the form of steam after reaching the predetermined temperature, thus obtaining high-purity butanone at the interception side of the pervaporation membrane separation unit, and putting the high-purity butanone into a product tank after the high-purity butanone is condensed by the preheater and a finished product condenser successively. The permeation side of the membrane separation unit is connected with the vacuum system; water and little butanone in the solution at the interception side penetrate through a pervaporation membrane in the form of steam, and then go into a liquid-liquid separator for standing and layering after being condensed by a penetrant condenser; the butanone phase of the upper layer goes into a storage tank and then goes into a raw material tank, while the water phase of the lower layer goes into a rectifying tower; butanone containing a certain content of moisture obtained at the top of the tower goes into the raw material tank; waste water obtained in a tower kettle is discharged from the bottom of the kettle. The process provided by the invention is simple in process, high in safety factor, low in investment on equipment, high in energy utilization rate, free of addition of the third component and high in recovery rate.