The phenomenon of stress concentration will occur at the corresponding position before the failure fracture of the long-distance pipeline.However, traditional non-destructive testing and magnetic flux leakage testing technology cannot make corresponding early-warning for stress concentration.The non-contact magnetic detection technology uses the characteristics of magnetic memory of ferromagnetic materials to collect and analyze the gradient of the space magnetic field above the pipe.It can find the stress concentration area of the material and the early damage of the material. The stress concentration area of Guangxi natural gas pipeline is successfully detected by non-contact magnetic detection technology.The metal magnetic memory detector is used to verify the excavation of points with greater hidden danger. The conclusion is consistent with the non-contact magnetic detection technology, which proves the feasibility of non-contact magnetic detection technology.