The phenomenon of wire electrical explosion refers to the physical process in which a high-power pulsed current is injected into a metal wire load within an extremely short period of time. Based on electrical explosion of wires in constraint tube with borehole, directional plasma jet was formed, and the characteristic of the jet has been investigated in this paper. The electrical parameters as well as the whole dynamic process during the discharge were recorded by current coil, voltage probe and high-speed camera. After analyzing, it is found that the discharge process is basically consistent for different borehole diameter, and the peak values of voltage and current reach 24.7 kV and 12.5 kA, while the deposited energy in the wire reaches 176.5 J. The electrical parameters show good consistency among these three conditions. And the generated jet has the highest temperature, the maximum development speed of 905.8 m/s and the longest duration of 734.16 μs at the borehole diameter of 2 mm. These properties provide the possibility of plasma jet in ignition and material preparation, which has a broad application prospect.