Abstract: A complete set of working flow of excavation validation for in-line inspection has been established, and the requirement for basic information preparation and its application has been proposed. The proposed surface locating methodology of excavation validation for in-line inspection based on pipeline body feature such as valve, T-piece and elbow can solve effectively the problems of inadequate surface references and bias locating, enhance the locating precision and reduce excavation work. By means of the proposed projection correction algorithm, error correction between surface mileage and pipeline mileage can be realized. In comparison to the traditional interpolation, this method is more intuitive, has high calculation efficiency, can reduce effectively the error in distance measurement and delivers locating more precisely. As a summary of various defect measurements, it can provide an effective guidance to the field defect measurements, ensuring the reliability of excavation data.