An ultrasound-negative pressure cavitation fractional precipitation method was developed to efficiently purify (+)-dihydromyricetin. The precipitation efficiency of the developed method was significantly higher than that of the ultrasound- and negative pressure-fractional precipitation methods. In particular, under an ultrasonic power of 180 to 250 W and a negative pressure intensity of -200mmHg, highly pure (+)-dihydromyricetin could be obtained with a high yield of up to 97.56% in only one minute of precipitation. Kinetic analysis results showed that when both ultrasound and negative pressure were introduced during fractional precipitation, the rate constant increased by 1.4 to 7.1 times compared to the conventional fractional precipitation, and the activation energy decreased by -1,299 to -4,550 J/ mol. In addition, the particle size of the precipitate was reduced by 1.9 to 4.0 times, and the diffusion coefficient increased by 2.3 to 5.0 times.