Due to the advantages of easy operation,high detection accuracy and economical advantages,the sub-bottom profiler has obvious advantages in the accurate detection of underwater pipelines.Based on the actual situation of the dredging project of the Shenzhen Tonggu channel,this paper uses the sub-bottom profiler to accurately detect the deep buried pipeline under the channel,and further explores the application range and application key technology of the sub-bottom profiler.The main conclusions obtained are as follows：the differences in wave impedance between the original soil layer and the riprap,the riprap and the pipeline near the submarine pipeline are large,and the clear detection image information can be obtained.The method of dragging the side of the middle of the ship and shortening the streamer is adopted to avoid the large swing of the towed fish and improve the plane detection accuracy.Keeping the attitude of the underwater fish catching stable,and using the filtering method to deal with the invalid waves generated by the ship noise and water flow,waves,etc.,this paper provides a basis for the future development of the submarine pipeline protection construction plan.