In response to the problem of treating sewage pipelines deeply buried under embankments, the application of fluidized solidified soil in engineering is deeply discussed. The treatment of sewage pipelines deeply buried under the embankment has always been a difficult problem in engineering technology. The sewage pipeline of the Ershibu River in Hefei City is buried 10 meters deep under the embankment, with an inner diameter of 1.4 meters and a total length of 5.0 kilometers. There are leakage and other issues that not only threaten the safety of the embankment structure, but also pose a risk of environmental pollution. The surrounding environment of the project is complex, and the excavation construction is greatly limited, making the traditional treatment methods difficult to implement. After scheme demonstration and comparison, the final solution for this project is to use fluidized solidified soil to seal the sewage pipeline under the embankment. This innovative solution can achieve the effective sealing without large-scale excavation, which significantly reduces the safety hazards of the embankment and saves the construction costs greatly. The practical results of this project provide the important references for similar underground pipeline sealing designs and have significant demonstration value in practical engineering applications.