In order to measure and image the ultrasonic wavefield in the whole non-contact field, the dynamic ultrasonic wavefield measurement and imaging method based on digital holographic interference was proposed. Based on the theoretical analysis of ultrasonic wavefield measurement, the principle of ultrasonic wavefield measurement based on digital holographic interferometry was studied. At the same time, the main measuring process and data analysis process for different cross-sectional of dynamic ultrasonic wavefield were studied. The reflection type digital holography system based on pulsed laser was designed, including optical detection subsystem, ultrasonic subsystem and synchronization control subsystem. The experimental results show that the dynamic ultrasonic wavefield can be measured and imaged at different moments in a time series. At the same time, the micro-defect sample is designed and detected by dynamic ultrasonic wavefield measurement. The experimental results show that the dynamic ultrasonic wavefield measurement method and system studied in this paper can effectively identify the minor internal defects in the specimen.