本文利用轴上声压分布计算了具有圆形截面球面聚焦超声换能器的近场声束宽 度，获得了束宽表达式。文中给出了各种频率下不同曲率半径、不同开口半径时的 束宽曲线。同时给出了具有矩形截面的球面聚焦换能器的各种束宽曲线。为研制超 声断层成像装置提供了理论参数。 In this paper, the near-field beamwidth of a spherical-section focused ultrasonic transducer with circular cross-section was calculated by using the on-axis sound pressure distribution, and the beam width expression was obtained. The curve of beam width with different radii of curvature and different opening radiuses is given in this paper. At the same time, various beam width curves of the spherical focusing transducer with rectangular section are given. It provides the theoretical parameters for the development of ultrasonic tomography device.