Abstract: Undersea pipeline failure and crude oil leakage existed due to geological disaster when undersea oil & gas pipeline crossed the complicated areas, such as complex undersea topography, morphology, strong current, areas near islands and estuary where wind, current and fide effected obviously. Hence, routine and due maintenance detection of pipeline route survey should be carried out by oil & gas operation company. This paper illustrates geophysical technique applied in maintenance detection of undersea pipeline, and the practice shows that accurate echo-sounder survey, sidescan survey and high resolution subbottom seismic profile and accurate navigation and positioning system is the good method to solve the problem.