The impedance matching of spherical focused ultrasonic transducer is one of the primary factors affecting the energy utilization efficiency in focused ultrasonic flow polishing system. To realize the efficient utilization of the vibration energy of the transducer, the front matching layer structure is design to achieve the impedance matching of the transducer and the abrasive flow liquid, thereby improving the transmittance of the transducer vibration energy in the liquid, and the back-matching layer structure is used to reflect the radiated vibration energy on the back of the transducer to reduce dissipation of radiated vibration energy on the back of the transducer. Based on the acoustic impedance matching theory and Kirchhoff’s theory, the influence of the front and back impedance matching structure of spherical focused ultrasonic transducer on the focal point sound pressure is studied theoretically, and experimentally, a novel impedance matching structure for spherical focused ultrasonic transducer is proposed. The experimental results showed that the focal point sound pressure was increased by 72.03% compared with that of the traditional structure.