Distributed database backup method, device and system

The invention discloses a distributed database backup method, device and system, and the system comprises a main node unit which is used for generating a plurality of node database backup commands according to a preset database sub-database sub-table; wherein each node database backup command is used for indicating a data sub-table needing to be backed up of the corresponding node database; and each sub-node backup module is used for backing up the data sub-tables needing to be backed up of the corresponding node database according to the corresponding node database backup command, generatinga backup file and copying the backup file to the shared storage server. According to the invention, the node database can perform backup operation at the same time; the situation that the backup tasksneed to be processed by batch application nodes in series is avoided, the backup duration of the distributed database can be shortened, compared with the prior art, the batch application nodes do notneed to be set to execute