A rotary interruption technology is expected to significantly promote the breaking performance of a high-voltage switchgear. When the technology is introduced into a fault current interruption, an arc plasma is driven to mitigate the erosion pattern of contact surface. However, there still remains little understanding on the arcing behaviors between a pair of rotating electrodes. In this paper, it presents a rotary electrode by accelerating the rotary motion of arc spontaneously. The objective of this paper is to investigate the arcing behaviors of a pair of rotating electrodes. A 3D magneto-hydrodynamic model is built up with a reasonable boundary condition, by considering the rotation of the electrodes. Three kinds of rotating speed are assigned, which include: 1000/π rad/s, 1000/2π rad/s, and 1000/3π rad/s, in order to investigate the influence of rotating speed on the characteristics of arc plasma. The arcing current of 100 A is assigned both in the simulation and experiment. A high-speed (Charge Coupled Device) CCD camera is used to investigate the evolution of the arc discharging mode.