In order to explore the enhancing effect of contact ultrasound on hot air drying process, ultrasound enhanced hot air drying of pear slices was performed. The effects of different ultrasound powers and drying temperatures on drying characteristics and several quality indicators of pear slices were studied. The results showed that the improvement of hot air temperature and ultrasound power could significantly reduce drying time, and the stronger ultrasound enhanced effects could be achieved at lower temperatures. The BP neural network model was applied to predict the process of ultrasound enhanced hot air drying with high fitting precision. The cavitation and mechanical effects of ultrasound could increase moisture mobility and rehydration rate, and could improve the contents of the nutrients in pear slices. However, too high temperature was negative to the retention rate of total phenols, total flavonoids and ascorbic acid which were heat-sensitive nutrient components. The analytic hierarchy process was applied to determine the optimal parameters of ultrasound enhanced hot air drying of pear slices as hot air temperature of 35 ℃ and ultrasonic power of 48 W. The corresponding total phenol content, total flavonoid content, V_C content and rehydration ratio were 408.88 mg/100 g, 157.94 mg/100 g, 42.36 mg/100 g and 3.32, respectively. Therefore, the reduction of drying time as well as the improvement of product quality could be achieved with the application of contact ultrasound on hot air drying of pear slices.