The evolution process concerning detonation of primer-free detonator was theorectically examined. Based on the previous study on DDT of high explosives, the DDT process of primer-free detonator was discussed, and major factors affecting the DDT process, such as the donor charge, transmission charge and the confinement conditions , were experimentally studied, respectively. Based on the results of experiments and analysis, the author proposed a new approach to the development of more reliable and structurally simple primer-free detonator.