The nonlinear effect of high-intensity sound waves produces the acoustic radiation force (ARF),which makes acoustic levitation and manipulation practical.Acoustic levitation has no special needs for the physical and chemical properties of the controlled objects and is hence a promising application prospect.The commonly used levitation schemes include the standing-wave and phased-array levitation systems.The standing-wave system is poor at spatial freedom,ARF along the non-axial direction,and levitation stability.The phased-array system requires a complex control system and a high production cost.Here,we propose a single-side acoustic levitation system based on confocal-focused transducers.By driving pairs of transducers with reverse phase mode,two anti-phase focused spherical waves interfere with each other,resulting in constant sound pressure of 0 Pa at the focus.The resulting potential well can achieve stable particle capture and levitation.First,we analyzed the theoretical feasibility of the system according to Huygens'principle.Then,depending on the finite element method,we studied the influence of structural and driving parameters on the sound field distribution,such as the angle between the transducer axis and the central axis of the structure and the excitation phase modes.Finally,we demonstrated the particle trapping and thus verified the potential though distribution under two kinds of excitation phase modes of the levitation system experimentally.We found these results as follows.The strength of the dominating potential well reaches the strongest as the structural angle is 45º.As the excitation phases are 0,0,π,π,the sound field owns three potential wells which capture three clusters of quartz sands;the primary potential well is stronger than the secondary one.As the excitation phases are 0,π/2,π,and 3π/2,the sound field owns one potential well and captures one cluster of quartz sands.The isosurface of wave intensity around the potential well is more comprehensive than in the previous phase mode.The four-phase excitation improves the levitation stability better.The proposed levitation scheme can realize stable single-or multi-position capture of high-density objects in the fluid.Moreover,it has the advantages of low cost and a high degree of freedom.