Abstract: When measuring modular multilevel solid-state transformers, a unidirectional structure is mainly used as a guide to suppress oscillations. During the process, the oscillation target cannot be continuously processed, resulting in ineffective suppression results. Therefore, a design and analysis of a modular multilevel solid-state transformer oscillation suppression method based on topology optimization is proposed. By constructing a topology model of a modular multilevel solid-state transformer, clarifying the resonant frequency, and making preliminary judgments on the oscillation situation under continuous operation conditions. Based on the judgment results, design an EPT oscillation additional damping controller to suppress loop harmonics in stages and output preliminary suppression results. Using pulse edge modulation to refine the suppression results and achieve the ultimate goal. The experimental results show that the loss value obtained by the newly proposed method is basically controlled below 0.8%, and the loss is relatively balanced, without continuous increase or decrease. The suppression effect is good, the suppression effectiveness is significantly improved, and the performance is more superior and reliable.