The invention discloses an enhanced extraction system based on ultrasonic excitation and acid fracturing integrated permeability enhancement for a coal seam, including an ultrasonic excitation and acid fracturing integrated drilling device, an ultrasonic control box and a mixing tank. The invention further discloses an enhanced extraction method based on ultrasonic excitation and acid fracturing integrated permeability enhancement for a coal seam. The invention has the advantages of realizing intercoupling of ultrasonic excitation and acid fracturing, improving the pore structure of coal, enhancing the connectivity between pores and fractures, promoting gas desorption and improving gas extraction efficiency of coal seams.