NOVELTY - Synthesizing naproxen ketal intermediate utilizing steam permeable coupling technique involves: mixing 6-methoxy-2-(2-bromopropanoyl)-naphthalene and neopentyl glycol in a reaction kettle, adding p-toluenesulfonic acid catalyst, and toluene, controlling temperature at 60-100 degrees C, stirring to completely dissolved the material to form homogeneous mixture; connecting the reaction kettle with a steam permeable membrane device into a loop, such that the gases in the two devices are in circulation and removing water by-product generated in the kettle using permeable membrane technology.    USE - For synthesizing naproxen ketal intermediate (claimed).    ADVANTAGE - The present method reduces the energy consumption in the synthesis; improves the yield of the final product; and also improves the use rate of the raw material.    DETAILED DESCRIPTION - Synthesizing naproxen ketal intermediate utilizing steam permeable coupling technique involves: a) mixing 6-methoxy-2-(2-bromopropanoyl)-naphthalene and neopentyl glycol according to a molar ratio of 1-0.25:1 in a reaction kettle, adding p-toluenesulfonic acid (1-10%) as catalyst, and toluene, controlling temperature at 60-100 degrees C, stirring to completely dissolved the material to form homogeneous mixture, where the amount of the total mass of the raw material in the reactor is 8-10 times; b) connecting the reaction kettle and a steam permeable membrane device into a loop, such that the gases in the two devices are in circulation, circulating the steam generated in the kettle reactor, into the steam permeable membrane device at a flow rate of 6-30 l/h followed by opening the vacuum pump side of the film to generate pressure difference, and create a vacuum of 30-50 kPa; separating water in the circulating gas using an osmosis membrane, penetrating water in the back side of the film discharged from the vacuum system, and separating water generated from the front side of the film that does not return into the reactor through the loop, as gas and stopping the circulation after 4-12 hours. The osmosis membrane in the steam permeable membrane is composed of a supporting layer and separating layer.