Abstract: Based on the internal inspection data obtained from a domestic long-distance pipeline using magnetic flux leakage technology, an analysis was conducted on pipeline defects by internal inspection data. The identification of mileage distribution and characteristic features of metal loss defects and girth weld defects within the pipeline were obtained. A preliminary analysis was carried out on the underlying causes of these defects. Combined with relevant standards and evaluation methods, an applicability assessment was performed for pipe segments containing defects, followed by a prediction of their residual service life. This resulted in recommendations for the timing of maintenance and repair activities on the pipeline. Field excavations were also conducted to compare the data of actual measurements and internal inspection and the rationality of the applicability evaluations. This work was expected to enhance the utilization rate of the internal inspection data, facilitating comparative analyses across different inspection rounds. Ultimately, it aims to facilitate smoother progression of subsequent internal inspection tasks.