Abstract: In order to study the features of load sensitive control system for hydraulic breaking hammer of impact and breaking rock roadheader, a power bond grap h method was applied to establish a system model and a state equation. Based on the circumstances, an Amesim was applied to set up the simulation model of system and simulation results showed there were pressure and flow impacts in the system. In order to improve the application performances of the hydraulic breaking hammer and to improve the efficiency and the service life of the impact and rock breaking roadheader, an load sensitive control system of the breaking hammer was improved. T he simulation analysis showed that the improved system had improved the pressure impact of the piston and valve core as well as the output flow impact of the pump.A mong them, the fluctuation frequency of the pump output flow was reduced by 50% in average and the pressure peak of the valve core for the pressure limited valve wa s reduced from 1.8 MPa to 0.3 MPa. The impact energy and impact frequency of hydraulic breaking hammer to be adjusted at any time could be realized and the simula tion verified load sensitive features of system.