An operation method and apparatus for a data storage system are provided, which relate to the field of data storage and enhance efficiency of a read operation on distributed stored data. The method includes: receiving, by a data node, a data operation message, where the data operation message carries a data operation type and a data object of an operation; querying a state parameter of the data object, where the state parameter is allocated to the data node by a management node, and is used to indicate an update state of the data object, and the update state includes a synchronous state, a semi-synchronous state and an asynchronous state; and if the state parameter is the synchronous state and the operation type is a read operation, reading the data object stored by the data node. Embodiments of the invention are used to operate data in a distributed data storage system.