By the method of model test,we study the evolution process of high pressure flush submerged jet of trailing suction hopper dredger,and use ultra-high speed camera to study the flow pattern of high pressure flush submerged jet in static and moving state.The experiment can not only provide the jet and diffusion state in submerged state,but also provide the basis for improving the design of trailing suction hopper dredger.The results show that when the pressure of ultra-high pressure water jet increases to a certain value,the shape of the jet forms a “lotus root” distribution state with large middle and small middle parts.Under the experimental condition,the moving speed has little influence on the evolution process of ultra-high pressure submerged water jet,and improving the high pressure can effectively solve the tailing problem in low pressure.