Abstract: Ultrasonic phased array technology has a very significant value in acoustic levitation. Compared with traditional onedimensional single axis acoustic levitation device,a phased focusing principle based on concave spherical with double emitter ultrasonic array is introduced, and a sound field with strong acoustic levitation ability is producd. What is more, the simulation and visual verification of the sound field are also mainly researched. First, its structure is introduced, and the acoustic theories such as phased focusing principle, ultrasonic standing wave suspension mechanism, sound pressure and acoustic radiation force are expounded. Afterward, according to the results of theoretical analysis, with the help of COMSOL multiphysics multi physical field simulation software, the phased focused ultrasonic field is simulated. The phase of each ultrasonic transducer which produces sound field can be controlled independently. Through the actualtime modification of phase, the sound field can be dynamically focused to realize the suspension and arbitrary trajectory movement of particles. Finally, the single reflector schlieren system is used to achieve the realtime visualization of sound field. Compared with the simulation results, the accuracy of the phase controlled focusing principle of the concave spherical double emitter ultrasonic device is verified.

Key words: concave spherical double emitter ultrasonic device, principle of phase controlled focusing, COMSOL simulation, schlieren method