Keywords: 
• underground pipeline /
• excavated /
• inertial navigation /
• software design

Abstract: [Introduction] This paper aims to solve the traditional geophysical methods such as pipeline instrument, ground penetrating radar, sonic detector, etc. by the limitations of its technology can not accurately determine the existing trenchless pipelines such as small diameter, large buried deep, non-metallic pipelines to obtain the space location of the difficulties, to avoid in the construction process because the pipeline can not accurately determine the location of the accident caused by the frequent occurrence of accidents. [Method] Aiming at the problem of trenchless pipeline detection, this paper put forward a detection technique based on inertial guidance to detect small diameter, large buried depth and nonmetal, designed and tested the three-dimensional measuring system of underground pipeline based on inertial navigation principle. [Result] The experimental results show that the software structure and function design of the three-dimensional measuring system of underground pipelines based on inertial navigation principle is reasonable, and the real space three-dimensional trajectory can be solved in real time for trenchless pipeline measurement.In the measurement process, the space trajectory of the pipeline can be displayed on the spot, the cross-sectional view and the three-dimensional views, the data can be stored and output, the output data format can be set according to different requirements, and the input requirements of the digitized geographic information three-dimensional data management system are satisfied. [Conclusion] The system can be applied to the detection of super buried depth, small diameter and any material, and its detection precision is high, which provides a good reference for the detection of urban difficult pipelines.