Abstract: Using of sound probe, sound-analyzing amplifier, hot-wire anemometer, computer data collecting and processing system, et al, the velocity wave patterns of fluid under various acoustic intensities were observed. Basing on the experimental results, the average velocity, pulsation velocity, frequency spectrum, velocity auto correlation, velocity and acoustic intensity cross correlation, et al, are calculated and analyzed. The experimental results show that the flow velocity field vacillates with the sound signal synchronously and proportionally. When the acoustic intensity reaches about 155dB, the sound field enters into a non-linear field and the signal pattern changes from sine wave to saw-tooth one, while the flow field changes in the same way. The oscillation and the non-linear effect induced by acoustic enhance the flow turbulence and will be beneficial to the particle agglomeration.