A stable 12-phase AC arc was successfully generated and applied in the field of glass in-flight melting, the arc behavior was characterized by image analysis. The effects of electrode configuration and sheath gas flow rate on arc and melting behavior of granulated glass raw material were investigated. Results show that different electrode configurations leads to various arc discharge and high-temperature region. The luminance area with high-temperature region and its fluctuation reflect the change of arc discharge behavior. The vitrification degree of glass raw material is mostly dependent on the center temperature of arc. As the sheath gas flow rate increases, the ratio of luminance area decreases and the center temperature of arc increases.