Two bi-directional-current multi-pulse converter topologies are proposed, which can achieve a bi-directional flow of energy in the traditional multi-pulse rectifier. When it is operating in the inverter state, the converter is equivalent to a multiplex current type inverter. Compared with traditional discrete current-multiplex inverter, the inverter has less number of the power and magnetic elements, and smaller size of the system. In this paper, a bi-directional 18-pulse converter is taken for example, and its working principle is introducted and the effect of the level angle is obtained with the minimum total harmonic distortion (THD) of a 18-pulse converter. A pulse-width modulation to achieve the voltage and current regulation in the AC and DC sides is proposed. Finally, simulation and hardware experiments verify the feasibility of the proposed system.