Abstract: This paper introduced the basic principle of rotary percussion drilling technology. The structure design, operating principle, performance test and parameter matching of hydraulically operated percussion tools were discussed in detail. The field practice proved that the rock - breaking efficiency of rotary percussion drilling can be increased 40%~49, 8% in comparison with rotary drilling. For medium harder formation, its service effect was more obvious, it can also reduce drilling cost, improve the quality of well bore and decrease downhole accidents. in the soft formation, adjusting the performance parameters of percussion tools and increasing rotary speed and percussion frequency properly, then the penetration rate can be increased too.