The highpressure water jet assistant machine, which can improve the efficiency of rock breaking, has advantages, such as high rock breaking speed, less abrasion of cutter tools, low dusty and movability. The stateofart of the study on the mentioned machine and the trend of the technology are analyzed. Influencing rules of rock characteristics and jet parameters on rock breaking effect are summarized. The breaking points and thinking of the study on the mentioned machine are proposed. The paper can provide references for application of rock breaking technology by means of highpressure water jut assistant machine.