Embodiments of the present invention discloses a wireless local area network data transmission method and apparatus, which are used for improving data transmission efficiency. The method includes: generating, by an access point (AP), a physical layer protocol data unit (PPDU) of a wireless local area network, wherein the PPDU comprises a Physical Layer Convergence Protocol (PLCP) header domain and a data domain, wherein the PLCP header domain comprises a preamble and a control domain, and the control domain carries duration information, wherein the duration information is used for network allocation vector (NAV) setting and protecting transmission of subsequent one or more PPDUs after the generated PPDU in a transmission opportunity (TXOP), and a duration indicated by the duration information includes transmission time of the subsequent one or more PPDUs after the generated PPDU in the TXOP; and sending, by the AP, the generated PPDU.