TheKarst landscape with many caves, reefs and steep bank slopes in the Hongshuihe river of Guangxi Zhuang autonomous region has brought great challenges to the passage of the long distance pipelines. In order to cross the Hongshuihe river, the Guangxi natural gas pipeline project has made some improvement to the general sinking pipe crossing technology in combination with the unique topography of the area. In the process of sinking pipe, the PE layer and the bend of the pipeline have been well protected, and the amount of earthwork excavated on both sides of the banks has been reduced. Therefore, the sinking technology of the floating pipe in Hongshuihe river is summarized, and the key construction technologies of the improvement is elaborated as well, which provides reference for the sinking pipe crossing under similar geological conditions.