The invention provides a lithium-battery-pack equalization control method and system based on a dynamic correction SOC. The method includes the following steps that the SOC of each lithium battery ina lithium battery set is obtained; the range rsoc of the battery set is calculated; the range rsoc and the preset range threshold are compared; the mean value (the symbol can be seen from the description) of the SOCs of all the lithium batteries are selected to serve as a balanced target SOC, charge equalization is conducted on the lithium batteries with the SOC lower than the value (the symbol can be seen from the description), and discharging equalization is conducted on the lithium batteries with the SOC higher than the value (the symbol can be seen from the description), wherein dSOC refers to an equalization control band. The method and the system have the advantages that the modularity is high, the balancing speed is high, the use efficiency of the batteries is improved and the service life of the batteries is prolonged.