The influences of the applied voltage, materials of electrode, and initial pH value of Acid OrangeⅡon the degradation efficiency of Acid OrangeⅡby gas-liquid gliding arc discharge are investigated. Intermediate products are detected by GC-MS. Metal scraps are analyzed by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX). The results indicate that under the conditions of carrier gas O2, and gas flow rate fixed at 0.4 m3/h, and wastewater flow rate of 20 mL/min, and the shortest electrode distance of 3.5 mm, solution concentration of 300 mg/L，applied voltage is 10 kV, material of electrode is stainless steel and initial pH value is acidic or basic, the optimal removal of Acid Orange Ⅱ solution can be achieved. Free radicals attack chromophore groups, benzene-ring and naphthol-ring cleave, then intermediates and small molecule compounds form in three kinds of carrier gases.The effects of conductivity is not obvious. The corrosion of electrode exists in non-equilibrium plasma zone, Fe atom dissolves selectively. The content of oxygen is much, and the main production is Fe2O3 and Fe3O4。