The invention relates to a series capacitor type high-voltage direct current breaker and a control method thereof. The breaker comprises direct current breaker units which are connected in series, and each direct current breaker unit comprises a change-over switch, a switching circuit and an energy consumption device which are connected in parallel. The change-over switch adopts a mechanical switch, and the switching circuit adopts a resistance capacitance branch circuit, and the energy consumption device adopts a lightning arrester. The high-voltage direct current breaker is connected with a control circuit, and the mechanical switch detects failure current and acts at the T1moment, and transfers the failure current into the resistance capacitance branch circuit. The failure current charges a capacitor, and controls switching-on and switching-off of the mechanical switch. Before the mechanical switch witches off at the T2 moment, charging voltage on two ends of the capacitor throughout is lower than arcing voltage at fractures of the mechanical switch. When the voltage on two ends of the capacitor reaches operation voltage of the lightning arrester, the control circuit controls the lightning arrester to act at the T3 moment so that energy can be released from the lightning arrester. According to the series capacitor type high-voltage direct current breaker and the control method thereof, the mechanical switch does not have electric arc, non-arc breaking off is realized, energy is released through utilization of the lightning arrester, quick extinguishing of the electric arc is realized, and the failure current is cut off.