In this paper, according to the buried depth requirements of the crossing section of the subsea pipeline, the commonly used lowering methods are analyzed and compared, including newly built pipeline nearby and lowering the live pipeline. Taking the location of nearby built subsea pipelines and cables, the water depth of the shipping channel, the seabed bottom soil and the pipeline parameters into consideration, the lowering and in-place stresses and the anti-floating evaluation have been assessed, it is recommended to lowering the live subsea pipeline by post-trench technology. Considering the ability of the post-trench equipment, comprehensively consider adopting step-by-step implementation and layered excavation to lay down the live pipelines, the key parameters of the lowering construction are analyzed, and specific implementation measures are given to provide reference for the implementation of subsequent projects.