Abstract: In order to fully mine the useful information of the internal and external inspection data of pipeline, the external inspection data is aligned against the internal inspection data, forming an alignment database of internal and external inspection based on the location information, so as to identify the main factors affecting the safe operation of pipeline. With reference to the engineering example of a natural gas pipeline, the alignment and comprehensive analysis of pipeline data were realized with the internal and external inspection data alignment method. The analysis results show that the pipeline is in a good state of cathodic protection. It is of little possibility for the soil resistivity and AC/DC stray current to form corrosion at the damage points of the external anticorrosive coating. In addition, no corrosion was found at the places with metal loss on the outer wall and at the damage points of the external anticorrosive coating of pipeline by excavation. Generally, the aligned internal and external inspection data is in favor of studying the impact of external environment on the safe operation of pipeline, further to improve the integrity assessment system.