为了保证海底管道与缆线的安全和稳定，人们采用了许多措施。其中，最为经济有效的方法是利用开沟机等相关设备将管道或缆线埋入海底。本文研究水下开沟，设计了一款具有轻型结构、可自主推进的水下射流开沟机，并对加工完成后的样机模型开展了水下开沟的试验。验证了所设计的开沟机在淹没状态下不仅可以完成自主推进工作，还能在管道流量达到50m3/h时破坏抗剪强度为8kPa的沙土，最大沟深可达0.41m，为后续的模型优化以及管线埋设提供理论与依据。

Many measures have been used to ensure the safety and stability of submarine pipelines and cables. One of the most cost effective methods is to use trenchers and other related equipment to bury the pipeline or cable into the seafloor. In this paper， a light weight， autonomously propelled underwater jet trencher has been designed and conducted underwater trenching tests on the machined prototype model to verify that the designed trencher can trench under submerged condition， and complete the autonomous propulsion work to destroy sand with shear strength of 8kPa when the pipeline flow reaches 50m3/h. The maximum ditch depth can reach 0.41m. This work provides the theory and basis for subsequent model optimization and pipeline burial.