Abstract: Using the finite element theory, this paper is concerned with, the dynamic characteristics of a cable-stayed pipe bridge of Zhongqing gas pipeline spanning Fujiang caused by the liquid column accumulation while pigging. The displacements, velocities,accelerations, stresses and strains of the bridge are calculated Through the analysis, the maximum length of permission of the liquid column and the maximum Vertical displacement of permission for the bridge are obtained at some pigging velocity.