NOVELTY - Device comprises a preprocessing system, a pervaporation membrane system, a condensation system, a product storage tank and a vacuum system. The preprocessing system comprises a fermentation tank set with multi-hole separating film device. A porous separating film device comprises a supporting body. The supporting body and the fermentation liquid set on one side surface of fermentation tank is set with an active film layer, while other side of the fermentation tank is connected to a raw material tank by a vacuum pipeline. The pervaporation membrane system comprises a pervaporation membrane.    USE - The device is useful for improving the fermentation efficiency of biomass fuel alcohol (claimed).    ADVANTAGE - The device can maintain the status of fermentation process under lower edge for separation, improves the intensity and the fermentation efficiency of fermentation process, maximizes the utilization rate of yeast fermentation, relatively shortens the period of time to obtain more fuel alcohol content, is simple, has less power consumption during the separation process, and easily integrates with the existing fermentation process.    DETAILED DESCRIPTION - Device comprises a preprocessing system, pervaporation membrane systems, a condensation system, a product storage tank and a vacuum system. The preprocessing system comprises a fermentation tank set with multi-hole separating film device. A porous separating film device comprises a supporting body. The supporting body and the fermentation liquid set on one side surface of the fermentation tank is set with an active film layer, while the other side of the fermentation tank is connected to a raw material tank by a vacuum pipeline. The pervaporation membrane system comprises a pervaporation membrane. The one side of the pervaporation membrane is provided with a raw material pump. The other side of the condensing system is connected to the raw material pump and the raw material tank. The condensing system comprises a condenser. The condenser is connected to the product storage tank. The vacuum system comprises a first vacuum pump and a second vacuum pump. The first vacuum pump is set on the vacuum pipeline set in between the supporting base and the raw material tank. The second vacuum pump is connected to the condenser. An INDEPENDENT CLAIM is also included for improving the fermentation efficiency of biomass fuel alcohol by using the device, comprising (i) preprocessing biomass raw material, and fermenting the biomass in the fermentation tank; (ii) transferring the fuel alcohol from the fermentation tank into the vacuum system under differential pressure through the porous separating film, and continuously extracting alcohol from the tank; (iii) pumping the fermentation broth into the pervaporation membrane, and subjecting to gasification process in the pervaporation membrane, and transferring the gaseous form fuel alcohol from the pervaporation membrane onto the other side of the pervaporation membrane for enrichment; and (iv) transferring the enriched fuel alcohol from the other side of the pervaporation membrane into the condensing system, condensing, and recycling the enriched fuel alcohol in the product storage tank.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the device.