本文视饱和砂土为流固两相介质，采用工程上通用的土力学模型，利用Ｌａｐｌａｃｅ变换求解了饱和砂土中球形洞室瞬态响应问题，得到了均匀受压球形洞室问题的解析解．经与弹性单相介质中均匀受压球形洞室对比，考察了流体对饱和砂土体动力响应的影响．本文为分析地下结构动力响应提供了一种有效的方法． This paper regards saturated sand as a fluid-solid two-phase medium. Using the general soil mechanics model in engineering, Laplace transform is used to solve the transient response problem of a spherical cavity in saturated sand, and an analytical solution to the problem of spherical cavity under uniform pressure is obtained. . The effect of fluid on the dynamic response of saturated sands was investigated by comparing with the uniformly pressurized spherical cavity in elastic single-phase medium. This paper provides an effective method for analyzing the dynamic response of underground structures.