Cavitations are not only the dominant mechanisms of the stone comminution in ESWL but also the leading factors for the tissue injury. This conclusion has been shown by the theoretical analysis, the numerical simulation, the experiments in vivo and in vitro and the practice of the clinic. This paper summarizes the development in the field of the cavitation in ESWL, which lays the foundation for the further study of the ESWL. There are many difficulties and challenges in the research of the ESWL which needs further study in the theoretical field , the innovation for the numerical methods, the amelioration for the experiment technology and a lot of serious clinic practices. Compared with the theoretical analysis and the experiment technology, numerical simulation is an economical and safe method for the research of ESWL.