This paper focuses on the three-level Buck-Boost Bi-directional converter (TL Buck-Boost BDC) applied in energy-storage inverters serving as charging or discharging circuit for storage battery. Based on the traditional dual closed-loop control method, a dual feedforward control strategy based on the balanced duty cycle signal at the midpoint of the direct current bus (DC Bus) and the battery voltage duty cycle signal is proposed. The balanced duty cycle signal at the midpoint of the DC Bus is generated by the balanced feedforward generator, and the battery voltage duty cycle signal is generated by the battery voltage feedforward generator. These two duty cycle signals are superimposed with the duty cycle signal generated by the dual closed-loop control to construct the duty cycle signal used to control the switching on or off of the switches in the TL Buck-Boost BDC, thereby achieving stable control of the charging or discharging operation in the energy-storage inverter while ensuring the DC-Bus voltage, Realized DC-Bus midpoint balance and improving the dynamic response speed of the system. The control parameters of the TL Buck-Boost BDC is designed, and the correctness and reliability of the method studied in this paper is verified by experimental results.