本文设计不了同焦距的菲涅耳超声透镜，并利用V型纹影光路实现了40 KHz超声场经过菲涅耳超声透镜后声场分布的可视化.根据经过菲涅耳超声透镜后声场分布的准直性，可以与传统的光学透镜焦距测量实验一样，在可视化状态下测量出声透镜的焦距.利用本文中的实验装置测量的声透镜焦距的结果与设计值符合得较好.本文提出的可视化环境下的声透镜参数测量实验装置，通过光学手段完成声学内容，实现了光学与声学内容在大学物理实验中的有机结合.

Fresnel ultrasonic lenses with different focal lengths are designed.The visualization of 40 KHz ultrasonic field distribution passing through a Fresnel ultrasonic lens is realized by using VSchlieren optical path.According to the collimation of sound field distribution after passing through Fresnel ultrasonic lens,the focal length of acoustic lens can be measured in the visualization state like the traditional experiment of measuring the optical focal length.The measurement results of the focal length of acoustic lens by using the experimental device are in well agreement with the design values.The acoustic measurement is completed by optical means,and the combination of optical and acoustic content in college physics experiment is realized.