In the three-phase inverter, traditional SVPWM algorithm involves vector coordinate transformation and decomposition. It has more trigonometric function operations, matrixes, and irrational numbers operations. The complex computation reduces the real-time requirements of the control system. This paper presents a SVPWM three-segment modulation and its calculation method and realization method. It has the advantage of simplifying the traditional SVPWM modulation calculation and can be completed through the look-up table and simple multiplication modulation. Sector's judgment and drive inverter bridge wave generation are realized by the combination of logic and implementation. Drive wave modulation can be realized by hardware or software. This paper describes the design principle and the requirements, and the SVPWM three-segment modulation is made of Simulink simulation and circuit experiment. Through the analysis, simulation and experiment, it is proved that the three-segment modulation of SVPWM and its calculation method are feasible.