The present disclosure is related to a method and an apparatus for data migration in a database cluster. The method includes obtaining a snapshot of a source data node and recording incremental data in a to-be-migrated data shard in the source data node according to inventory data. The method includes migrating the inventory data to a target data node. The method also includes migrating the incremental data, and during the migration when the unmigrated incremental data satisfies a preset write-lock condition, instructing the source data node to perform a write-lock operation on the to-be-migrated data shard and migrate unmigrated incremental data to the target data node. The method further includes, after the migration of the incremental data is completed, instructing a coordinator node to switch a route corresponding to the to-be-migrated data shard from the source data node to the target data node.