Embodiments of the present disclosure disclose a data communication method and apparatus. The data communication method includes: when receiving a PPDU, obtaining, by a network node, a BSS identifier in the PPDU; if the BSS identifier in the PPDU is different from a first BSS identifier, and the BSS identifier in the PPDU is the same as a second BSS identifier, determining whether the PPDU meets a preset spatial reuse condition, where the first BSS identifier is an identifier of a first BSS to which the network node belongs, the second BSS identifier is an identifier of an extended BSS to which a target relay belongs, and the target relay and the network node belong to the first BSS; and if the PPDU meets the preset spatial reuse condition, contending for an access channel, and communicating with a station other than the target relay in the first BSS.