The invention relates to a drying device and method using contact ultrasound to strengthen low-pressure superheated steam. The device is equipped with a drying box connected with a vacuum pump, a boiler, a steam storage tank, an ultrasonic generator, an ultrasonic transducer and an ultrasonic radiation plate , the boiler is connected to the steam storage tank through a conduit, the steam storage tank is connected to the drying box through a conduit, and a steam injection port is provided in the drying box at the connection point, the ultrasonic transducer is arranged in the drying box, and the drying box is connected to the drying box through a wire. The ultrasonic generator outside the box is connected, and the ultrasonic radiation plate is set on the ultrasonic transducer; this method uses low-pressure superheated steam as the drying medium, on the one hand, the boiling point of the water in the material is reduced through the low pressure, which is conducive to the evaporation of water, on the one hand, it is different from the normal Compared with high-pressure superheated steam, the use of low-pressure superheated steam reduces the drying temperature, thereby reducing the risk of thermal decomposition of active ingredients to a certain extent, while ensuring a higher drying rate.