Abstract: Triple-active-bridge (TAB) converter has received wide attention in the field of the DC micro-web and the hybrid energy storage due to multiple voltage levels can be connected flexibly with it. To improve the dynamic performance of the TAB converter and achieve port decoupling function, model predictive control is an effective strategy. To solve the complexity with the power transfer model, the high difficulty and the high cost with the continuous-control-set model predictive control, a phase-shift discretized-control-set model predictive control method was proposed combined with finite-control-set model predictive control to control the TAB converter and improve the application value of the TAB converter. The method was arranged to achieve a global optimal control step by step, finding the optimal combination of finite discrete phase shifting angles in each control cycle. The results show that the proposed method can not only guarantee excellent dynamic performance and decoupling performance, but also avoid the complexity in nonlinear equation solution, enhancing the practicability of the control strategy greatly. Analyzing and optimizing the main influencing factors, the weight coefficient, the discrete gain and prediction range of the phase-shift discretized-control-set model predictive control, experiment results verify its effectiveness.