Heat and mass transfer film for total heat exchanger and preparation method thereof

The invention relates to a heat and mass transfer film for a total heat exchanger and a preparation method thereof. The heat and mass transfer film comprises a hygroscopic base material with multiple through holes and hydrophilic polymer solution films. The hydrophilic polymer solution films are coated on upper and lower surfaces of the body of the hygroscopic base material and block the multiple through holes of the hygroscopic base material. The multiple through holes are uniformly distributed in the hygroscopic base material and run through the upper and lower surfaces of the hygroscopic base material. Parts of the hydrophilic polymer solution films blocking the multiple through holes have thickness less than the total thickness of the body of the hygroscopic base material and the hydrophilic polymer solution films so that the heat and mass transfer film of which upper and lower surfaces are provided with multiple depressed areas is formed. The heat and mass transfer film can improve hygroscopicity and reduce heat conduction and moisture conduction resistance under the premise of good use intensity. Through nonuniform thickness of the heat and mass transfer film, air-flow disturbance is improved and an air-to-film convective mass transfer capability is improved.