The topology of the MMC is suitable for High Voltage Direct Current Transmission (HVDC). However, during operation, internal circulating currents are easily generated, which can lead to arm current distortion, increased system power losses, and reduced stability. In response to the limitations of the P-ROQR controller, such as its restricted control accuracy and insufficient robustness, this paper proposes a circulating current suppression strategy based on the P-ROQR+Q-FRC controller. By introducing the Q-FRC controller on the basis of the P-ROQR controller, the second and fourth harmonic circulating current components are effectively suppressed, and the implementation is simple. To verify the effectiveness of the proposed method, MMC-HVDC simulation experiments were conducted under the same conditions: during steady-state operation, DC voltage sags, DC voltage fluctuations, and three-phase unbalanced operation. The results demonstrate that the MMC equipped with the P-ROQR+Q-FRC circulating current suppressor outperforms the one using the P-ROQR suppressor in both dynamic response and circulating current suppression capability. Specifically, the fluctuation range of the circulating current is reduced by 57.14%, and the fluctuation range of the submodule capacitor voltages is decreased by 7.5%. Consequently, the P-ROQR+Q-FRC suppressor is more suitable for MMC converters.