The invention discloses an ultrasonic and hot air combined carrot drying method and an ultrasonic and hot air combined drying device. The ultrasonic and hot air combined carrot drying method comprises the following steps of: (1) pretreatment of a carrot raw material, namely washing and slicing fresh carrots; and (2) ultrasonic and hot air combined drying, namely, putting carrot slices on a sieve, sequentially starting a heating and blowing device and an ultrasonic irradiation device, and carrying out ultrasonic and hot air combined drying on the carrot slices, wherein the drying temperature is 30-70 DEG C, the drying air speed is 0.3-3m / s, the ultrasonic power is 100-200W, the ultrasonic frequency is 20kHz, the distance between the ultrasonic irradiation device and the sieve is 5-15cm and the drying time is 3-6 hours. According to the ultrasonic and hot air combined carrot drying method, an ultrasonic technology is directly and effectively coupled to a hot air drying process, so that the heat transfer and mass transfer efficiencies in the drying process are improved, the drying time is shortened, the energy consumption is saved and the product quality is improved.