In this paper, the oscillation mode of wind power through DC transmission system is analyzed, and the interaction mechanism between the circulating current zero sequence component of MMC system internal oscillation and capacitor voltage is revealed. The mechanism of the internal oscillation of MMC system caused by the interaction between the zero sequence component of the circulating current and the capacitor voltage of MMC is revealed. The dynamic relationship between the total energy stored by the equivalent capacitance of each arm of the MMC system and the zero-sequence current is constructed. The differential modulus and the common modulus of the total energy stored by the equivalent capacitance of each arm of the MMC system are derived. The zero-sequence current control strategy is proposed. The dynamic model of the control strategy is constructed, and the oscillation mode of MMC system with zero sequence current control strategy is analyzed after considering the intermediate variables of the model. The results show that the proposed control strategy can make the real part of the oscillation mode move left and increase the total damping. The electromagnetic transient simulation model of wind power through DC transmission system with zero sequence current control strategy is constructed. The simulation results show that the proposed strategy greatly increases the damping level of the system, improving the stability.