Abstract: The present invention is in the field of composite material manufacturing technology, and relates to a prefabricated fabric for liquid molding composite material and a preparation method thereof. The prefabricated fabric comprises a basal fiber fabric, which is characterized in that one or two surface(s) of the basal fiber fabric is(are) conglutinated with a toughening layer. The method for preparing the prefabricated fabric comprises the steps of conglutination of toughening layer, and conglutination of tackifying layer. The prefabricated fabric has both the interlaminar selective toughening and tackifying functions, and realizes the high toughness modification of the composite material while keeping the composite material liquid molding processibility and the good tackifying performance.