The invention relates to a fast data synchronization method in continuous data protection technology. The method is technically characterized by including the steps of firstly, establishing correspondence between all data blocks in disk partitions and a write operation status bitmap in a production terminal device; secondly, synchronizing for the first time, namely copying all the data blocks in the disk partitions in the production terminal device to an image storage region in a target terminal; thirdly, performing progressive synchronization, namely calculating the number of the data blocks, engaged in write operation, in the disk partitions during synchronization; if the changing number is lower than a set threshold, interrupting front-end application of the production terminal device to quickly complete synchronization of the changing data blocks; and if not, copying the data blocks, engaged in write operation, to the target terminal. The data blocks which change in data synchronization are recorded by the write operation status bitmap, the changing data blocks are determined according to the bitmap so as to achieve quick data synchronization, and accordingly data synchronization efficiency is improved. The method has the advantages of high timeliness, fast processing, safety and reliability and the like.