Abstract: A set of continuous silk electric blasting powders making equipment was developed. Wire electric explosion tests were conducted on copper wires with wire diameters of φ0.3 mm, φ0.4 mm and φ0.5 mm at initial charging voltages of 9k V, 11 kV and 13 kV. The microstructure, particle size distribution, electrical signal waveform, and energy of the prepared ultrafine Cu powders were analyzed. The results show that the micro-morphology of ultrafine Cu powders prepared by wire electric explosion is spherical or quasi spherical, and the particle size is close to normal distribution. As the energy density of the input Cu wire increases, that is, increasing the initial charging voltage or decreasing the copper wire diameter, the powders particle size transforms from micrometer to nanoscale. Therefore, the distribution of powders particle size can be controlled by adjusting the energy density of the input copper wire.