The invention provides a data synchronization method which comprises the following steps: storing a data table T-i in a slave library i, and storing a data table T in a master library, wherein the stored record format of the data table T is the same as the stored record format of data table T-i; establishing a modified history list T-i-act in the slave library i; establishing a modified history list T-act in the master library, reading and acquiring effective operation increment from the slave library i when the synchronization time reaches, then packing the effective operation increment, the recorded contents and the initial master library version number stored in the previous synchronization, and uploading the uploaded package to the master library; counting to obtain the effective operation increment after the master library is warehoused, packing the effective operation increment, the recorded contents and the current master library version number, and returning the returned package to the slave library i; performing entry operation on the slave library i, and thus finishing a data synchronization process. According to the data synchronization method, synchronization of data tables between the master library and multiple slave libraries can be simply, rapidly and reliably realized at high efficiency.