The problems of low utilization and high cost of traditional arc suppression devices can be effectively solved by a multi-function arc suppression device （MF-ASD ）.However，active power is consumed by the MF-ASD during arc suppression.How to realize the DC-link voltage stability of the active module without an additional power supply unit is worth further discussion.An arc suppression method for grounding faults based on an additional energy loop is proposed.First，the topological structure and working principle of the MF-ASD are briefly described.Second，the influence mechanism of traditional arc suppression methods on the output active power and energy flow direction of the MF-ASD is analyzed，and the internal reason for the change in DC-link capacitor voltage is clarified.Third，an additional energy loop is constructed between the power grid and the MF-ASD to compensate for the active power and reactive power required for the DC-link voltage stability of the MF-ASD during arc suppression，thereby solving the problem that single line-to-ground faults cannot be stably suppressed.Finally，the effectiveness and feasibility of the proposed method are comprehensively verified by simulations and experiments.