The high-pressure jet at draghead is recognized as the most important dredging machine for the modern dredging industry, and its hydraulic efficiency is more effective than mechanical efficiency, so the best way to improve the efficiency of dredging is to improve the design of high pressure jet at draghead. Based on the theoretical analysis and with the the test method of locale, we find the rumale of high-pressure water breaking ground depth and improve the design project and put forward the conception of high efficiency draghead design.