To suppress the influence of low-frequency fluctuating power of a DC bus on an energy storage system, a low-frequency fluctuating power suppression strategy based on single-objective fixed-frequency model predictive control (MPC) is proposed. A flying capacitor bidirectional DC converter is the research object. To reduce the computational load of a traditional MPC algorithm, a single-objective fixed-frequency MPC control algorithm is proposed by analyzing the mathematical model of the converter. It can control the system current and the voltage of the two-terminal flying capacitor only through the single-objective constraint function of the inductor current, without independent optimization of the voltage of the two-terminal flying capacitor. In this way it greatly reduces the amount of calculation. In order to suppress the low-frequency fluctuating power of the energy storage system, a low-frequency fluctuating power suppression algorithm is introduced. Through the integration with the proposed MPC algorithm, the final control scheme can have the capability of suppressing the low-frequency fluctuating power and keep good dynamic performance while realizing the energy storage control goal. The proposed control strategy is verified by building a low-power experimental platform