The ground-breaking performance of the high-pressure flushing nozzle has a significant influence on the dredging efficiency of the trailing suction dredger.The ground-breaking performance of the high-pressure flushing nozzle is studied based on the experiment test.The results show that with the increase of the target distance,the ground-breaking depth of the high-pressure flushing nozzle gradually decreases and the ground-breaking width gradually increases;with the increase of the nozzle outlet pressure,the ground-breaking depth gradually increases and the ground-breaking width gradually decreases;with the increase of headway,the ground-breaking depth and width gradually decrease.Comparied with the ground-breaking performance of the high-pressure flushing nozzle with and without wear blocks,the overall change trend of the ground-breaking characteristics of the two nozzles is basically the same.When the nozzle is at the same distance from the mud surface,the ground-breaking depth and width of wear block high-pressure flushing are both larger than those without wear block,and the comparison of ground-breaking width is more obvious.