The invention relates to a method for vacuum-film drying and recovering an extracting agent in a coal-based oil residue extract. The method comprises the following steps of (1) adding an asphalt oil residue containing washing oil into a primary thin film drying machine, and indirectly heating to obtain an oil residue with the washing oil content being 5 percent to 20 percent and light-oil steam; (2) adding the oil residue with the washing oil content being 5 percent to 20 percent into a secondary thin film drying machine, and indirectly heating to obtain an oil residue with the washing oil content being 5 percent to 0.5 percent and heavy-oil steam; cooling and ejecting the light-oil steam, and thus obtaining unset light-oil steam and a little dust A; (3) cooling the oil residue with the washing oil content being 5 percent to 0.5 percent to obtain an oil residue with the temperature being 30 DEG C to 100 DEG C; cooling and ejecting the heavy-oil steam, and thus obtaining unset light-oilsteam and a little dust B; (4) mixing the unset light-oil steam and a little dust A and the unset light-oil steam and a little dust B to form mixed washing oil steam, and cooling to obtain condensedwashing oil; (5) cooling the condensed washing oil to obtain washing oil with the temperature being 30 DEG C to 100 DEG C. The method provided by the invention is low in investment, easy to implement,and high in benefit.