This paper presents the maximum constant boost control method based on the space vector pulse-width modulation (SVPWM) technique for a three-phase Z-source inverter (ZSI). The advantage of the proposed control method is not only it retains the advantages of the carrier-based maximum constant boost control strategy but it also inherits good features from SVPWM technique. Compared with the carrier-based control strategy, the proposed control method has a wider linear operation range and is easier for digital implementation. What's more, the number of switching transition in each switching cycle is reduced, which indicates less switching loss. The proposed control method will be beneficial for the further industrial applications of the ZSIs. The simulation results in Matlab/Simulink have also been provided, which have validated all theoretical analysis in the paper.