The invention discloses an MMC (modular multilevel converter) capacitor voltage equalization control method suitable for an FPGA (field programmable gate array) in the technical field of power systemoperation and control. According to the method, several sub intervals are divided according to the fluctuation range of a capacitor voltage during normal operation, a sub module is matched into a corresponding sub interval group according to real-time collected capacitor voltage, and thus the reading order of each group is determined according to a bridging arm current direction. At the same time,for a sub module with capacitor voltage near a rated value during the grouping, the switching state at a previous moment is considered, and the switching frequency of a device is further reduced by following the principle of maintaining the original state as much as possible. The method has the advantages that the ordering of the capacitor voltages of the sub modules is avoided, under the premiseof ensuring the equalization control effect of the sub modules, the rapid voltage equalization control can be realized, and the switching frequency of the device can be reduced.