The present invention relates to an energy storage-based distributed system bus-bar overvoltage suppression control method and system. According to the energy storage-based distributed system bus-barovervoltage suppression control method and system, the actual voltage of a bus-bar is acquired; related processing is carried out according to the value of the actual voltage of the bus-bar and an expected stable value, so that a converter corresponding to an energy storage system can be controlled, and therefore, the overvoltage of the bus-bar can be suppressed; and if the value of the actual voltage of the bus-bar does not drops to a normal range, the state of the energy storage system is changed under control so as to be converted from a discharged state to a charged state, and as a result,surplus power on the bus-bar is charged to the energy storage system, and the voltage of the bus-bar can be decreased, and over-voltage suppression is realized. The method includes two parts, whereinthe first part is the initial suppression of the over-voltage; when the initial suppression cannot make the voltage of the bus-bar drop to the normal range, then the state of the energy storage system is changed so as to be converted from the discharge state into the charged state, and at this moment, the energy storage system is equivalent to a power consumption load which consumes the extra power on the bus-bar, and therefore, the voltage of the bus-bar can be reduced, and the suppression of the over-voltage of the bus-bar can be realized.