A space-vector-control strategy for SMC, based on balancing the voltage of capacitors, is proposed in this paper, applying space-vector-modulation(SVM) algorithm to SMC(Stacked Multicell Converters), which is a novel topology of convertors. Through research on the topology of five-level SMC, every available switching state of a single phase is found and the effect of each switching state on capacitors’ voltage is analyzed. The strategy adjusts the voltage of flying capacitors and dc-link capacitors only by selecting switching states, without changing the redundant space-vectors and their duty cycles, which are calculated by the SVM algorithm. Therefore, the strategy is able to apply any SVM algorithm to five-level SMC, inhibiting the flying capacitors and dc-link capacitors’ neutral-points shifts. A model of SMC is built in matlab/simulink for simulation. The result of the simulation confirms the strategy’s validity.