The invention relates to a non-sorting searching method and MMC voltage-sharing method based on the same. A modular multi-level voltage source converter-high voltage direct current (MMC-HVDC) system has strong advantages on the aspect of improving power quality renewable energy source grid-connected island power-supply nonsynchronous interconnected urban mains supply. The stabilization of a sub-module capacitor voltage is crucial to the stable operation of the MMC, but the capacitor voltage balance of each sub-module of the MMC is the difficulty of the MMC. Compared with the existing sub-module capacitor voltage sorting voltage-sharing, the method disclosed by the invention has the advantages that the sorting operation on the whole bridge arm sub-module capacitor voltage is unnecessary, the algorithm execution time is greatly reduced; the occupied resource is less than the sorting algorithm, and the utilization rate of a chip is improved; the method can be applied to the voltage-sharing control on the high-voltage grade voltage source converter-high voltage direct current sub-module.