Abstract: In order to obtain the dynamic characteristic curve of the water powered DTH hammers impact system,analyzed the structure and motion process of the impact system.Based on the theory of power bonding,built the AMESim simulation system test model of the impact system,and obtained the dynamic characteristics curve such as displacement,velocity,acceleration of the piston and the valve core.For further study,take the impact pressure,the impact flow and the piston quality as dependent variable,the influences of impact velocity,impact frequency and impact energy on impact performance parameters were studied respectively.The results showed that the impact performance parameter increased linearly with the impact pressure,increased with the impact flow rate,and the trend is first fast and then slow,and the piston mass played a decisive role in the output capability of the impact parameters.