Abstract: The CIVA software is the professional simulation platform which is applied to nondestructive inspection.It is composed of simulation,imaging and analysis.It can be used to design or optimize the detection process,in predicting the actual ability of NDT inspection.In this paper,the ray inspection process of plate butt welding and tube butt welding was modeled and simulated using simulation platform of CIVA.The effects of radiation source,transillumination,exposure times and other parameters on the radiographic inspection film quality were studied.The results show that the simulation platform of CIVA can effectively reproduce the Radiographic inspection process,and predict the actual process of detection,so as to achieve process optimization of radiographic examination.