Abstract: The presence of additional stress-strain reduces the tolerance of the girth weld for defects and mechanical properties of pipe material and may lead to the further extension of defects to failure. Long-distance oil and gas pipelines are susceptible to large additional stresses in the pipeline body due to external loadings when passing through the geologically-hazardous areas such as mountains and permafrost. Therefore, it is in urgent need of reliable technical means to investigate the stress risk of the pipeline body to ensure the safe operation of pipeline. Herein, full-scale pipeline tests of three pipe materials, i.e., S355, S235 and X65, were conducted based on the full-scale traction test platform, so as to research the comprehensive application of inline inspection technology for the mechanical properties and stress-strain state of pipe materials. The results indicate that the inline inspection technology for mechanical properties of pipe materials is a new one based on the premagnetized electromagnetic eddy current inspection, which can inspect the yield strength of pipe materials effectively and identify the pipe material used in different pipeline sections accordingly. This technology can be used to predict the compatibility of girth welds with the strength of base metal, thus providing a new method for the rapid inline inspection of mechanical properties and the later integrity assessment of pipe materials. In addition, this technology is a useful supplement to bending strain in-line inspection technology based on the inertial navigation inspection unit, so that the stress-strain state of pipeline body can be inspected thoroughly, to timely discover and effectively prevent the pipeline failure due to large additional stress.