To study the ecological reef clearing technology in the environmentally sensitive area of the Yangtze River channel，the field test of underwater reef clearing with high frequency hydraulic breaking hammer is carried out to study the underwater reef clearing characteristics of high frequency hydraulic breaking hammer and optimize the reef breaking parameters.The test results show that the speed of the drilling rod embedded in the reef gradually decreases with the increase of the contact surface between the drilling rod and the reef.With the increase of strike time，the embedment depth of the drilling rod experiences three stages in turn：steep increase，slow increase and constant，corresponding to the high efficiency rock breaking，low efficiency rock breaking and ineffective rock breaking stages of the high frequency hydraulic breaking hammer in turn.The single optimal strike time of high frequency hydraulic breaking hammer is 20 seconds and the optimal strike distance is 0.3 meters.The research results have important reference value for enriching underwater ecological reef clearing technology in environmentally sensitive areas.