Abstract: Aiming at the problem of insufficient sound power at the focal point of the Archimedean spiral phased array transducer, the relationships of the array element shape and frequency with the change of the acoustic field are discussed by finite element simulation separately from the aspects of focal sound pressure, deflection range, grating lobe level, and focal region size. The results show that at the same frequency, the focal point pressure of the Archimedean spiral phased array transducer composed of sector-shaped array element increases by 32.28% compared with the circular array element, and the deflection range is 20 mm×20 mm×40 mm; moreover, at the selected frequency of 0.9- 1.0 MHz, the former phased array transducer can not only get a larger focal point pressure but also can guarantee the focusing quality. This article provides a useful design reference for increasing the focal point pressure of the Archimedean spiral phased array transducer and achieving its higher output power required in the deep tissue ablation.