Abstract: Based on theoretical analysis of current technologies, it is pointed out that developing high-efficiency drilling methods on the basis of new combined water jet is a good approach. A concept of pulsed abrasive water jet drilling technology, using bottomhole cuttings, is put forward, and the corresponding drilling tool is designed. The rock-breaking mechanism, assisted rock-breaking mechanism of this new drilling technology is analyzed, and the lab rock-breaking experiment of post-mixed pulsed abrasive water jet is carried out. The results show that the erosion volume grows with the increment of pump pressure, there are best rock-breaking jet length, abrasive concentration and particle size. In low concentration, the erosion energy of post-mixed pulsed abrasive jet is close to the pre-mixed pulsed abrasive jet. After the external fluid is drawn in, the jet dynamic pressure increases by 7%, while pulse amplitude increases by 150%. The above research lays solid foundation for the development of drilling tools with pulsed abrasive water jet using cuttings and related technology.