In an active-active system, if write lock permission is granted to a second storage array, a first storage array sends to-be-written data and a lock revocation request together to a lock server; the lock server sends a lock revocation request carrying the to-be-written data to the second storage array; after storing the to-be-written data, the second storage array sends a lock revocation success message to the lock server; the lock server gives the write lock permission to the first storage array; and the first storage array obtains the write lock permission and stores the to-be-written data.