Virtual offline desktop block device storage synchronization method

The present invention discloses a virtual offline desktop block device storage synchronization method. The method comprises the following steps: a synchronizing side reading virtual disk data, and sending a starting position and length information of the data to a synchronized side; the synchronizing side calculating a check sum; the synchronized side reading the virtual disk data according to the received starting position of the data, and calculating the check sum; and the synchronized side sending the calculated check sum to the synchronizing side, and the synchronizing side comparing a self-calculated check sum with the received check sum, if the check sums are different, sending the disk data, if the check sums are the same, taking no action, and if the synchronized side receives the disk data, writing the data into a local virtual disk. In the present invention, a block-by-comparison method is adopted, a next data block cannot be processed before completion of comparison and synchronization of the current data block, and once a failure occurs, a problem can be more quickly positioned in an operation on the data block compared with comparing multiple data blocks by the method, thereby further investigating a cause of the problem.