The invention provides a data communication method, including: sending, by the first electrical node, request information to an electrical node, where the request information is used to request an expected data volume quota of a first VOQ, and the first VOQ stores at least one first data packet to be sent to the electrical node; receiving response information, where the response information includes a target data volume quota; and sending the at least one first data packet to the electrical node via the at least one optical node based on the target data volume quota.