Abstract: The high current ion source is the core component of the 5 MW neutral beam injection heating system of HL-2M device. The ion source generates plasma by the collision between the gas molecules and primary electrons which are accelerated to high energy state by arc power supply (APS). So the APS is very important for the ion source to maintain a stable arc discharging. A model of the APS main circuit was built. The constant current control and notch control of the arc current and constant current charging control and constant power discharging control of the super capacitor were designed and simulated. This method not only can improve the efficiency of the APS main circuit analysis and design and shorten development cycle of the power system, but also can be used in fault analysis and control parameter tuning of the practical system for reducing the risk of experiment. The experimental results indicate that the output of the APS is in accord with simulation output.