A gliding arc plasma is utilized to strengthen a Ma1.2 supersonic jet flame. High-speed camera (10 kHz or 54 kHz), high-speed CH* emission (20 kHz) and OH PLIF (Pulsed Laser-Induced Fluorescence) are used to characterize the dynamic process of the supersonic jet flame assisted by the gliding arc plasma. The result shows that the gliding arc maintains the discharge at a lower power consumption of 230 W with a glow-type mode in the supersonic jet flame. When the plasma is applied, the intensity and area of the supersonic jet flame significantly increase. As the power consumption increases, the ratio of the flame intensity increases is higher, which can reach to 22.9%. It can be observed that the plasma assists in igniting the fuel to form the flame kernel in the supersonic flow, which develops into a flame fragment and supplies to the original flame. Meanwhile, the thickness of the OH groups is significantly widened after the application of the plasma. The reason may be that the fuel is pre-heated by the thermal effects of the gliding arc plasma, and the plasma-generated radicals such as OH and E are beneficial for the combustion, which increase the temperature of the reactants and reduce the activation energy to enhance the combustion efficiency.