Abstract: Computer Tomography referred to as CT,which is taking advantage of an object around a certain physical quantity obtained by one-dimensional projection data,through computer processing,given the level of the physical reconstruction of two-dimensional images and constitutes the basis of a two-dimensional image of the three-dimensional image technology.This paper introduces the application of seismic CT survey method of section arrangement in the Bajiaoqing tunnel.Considering the cracks appeared in the Bajiaoqing tunnel collapse occurred in central of uplink,downlink of Bajiaoqing tunnel,we have surveyed this area according to the designed plan.After the data collecting,data processing,geological interpretation and other meticulous work,anticipated results are achieved from this survey.