Abstract: Stress-strain monitoring technique is adopted for relaying the pipe section in Dongyugou of Lanzhou-Chengdu-Chongqing Oil Product Pipeline. Taking stress-strain monitoring on the pipe section relaying as a basic starting point, its stress at axial/hoop direction and 45° direction as well as variation tendency of maximum principal stress are analyzed for the pipe unit located at boundary point, bending area, transition section and maximum deflection location. Combined with elastic failure theory, the safety status of the relaying pipe section is evaluated and mechanics monitoring theory on pipe relaying process based on stress-strain monitoring technique is put forward.