Abstract: Water supply networks are important components of lifeline engineering. Because of the influence of random earthquake motion fields, their seismic response and function also have obvious randomness. The influence of the complicated topological structure of water supply networks cannot be considered by the traditional seismic response analysis of buried pipelines. The traditional method is also difficult to be applied to analyze the random vibration of the nonlinear system. The physical response of pipelines has not been implemented into the functional analysis of water supply networks. To solve these three problems, this paper modifies the random physical model of seismic ground motion fields on the local engineering site, introduces a finite element method of buried pipe networks, combines the probability density evolution method, and realizes the random seismic response analysis of water supply networks. Furthermore, the transient flow theory is utilized, and the random seismic function analysis of water supply networks is completed. It lays foundation for the seismic reliability evaluation of water supply networks.