A data transmission method, comprising: generating a physical layer packet of a first protocol version of a wireless local area network, wherein the physical layer packet comprises a preamble, the preamble comprises at least a legacy preamble that complies with a second protocol version of the wireless local area network and a first signaling field following the legacy preamble, the first signaling field comprises at least two OFDM symbols, the first two OFDM symbols of the first signaling field each comprises five signal segments, and duration of each signal segment is 0.8 microseconds; and five signal segments of a first OFDM symbol are respectively a fourth signal segment, a first signal segment, a second signal segment, a third signal segment, and the fourth signal segment in sequence; and sending the physical layer packet to a receive end device, so that the receive end device performs recognition, characterized in that the first protocol version is a version of an 802.11ax device, the second protocol version is an earlier protocol version than the first protocol version and five signal segments of a second OFDM symbol are respectively the first signal segment, the second signal segment, the third signal segment, the fourth signal segment, and the first signal segment in sequence, wherein the sending the physical layer packet to a receive end device, so that the receive end device performs recognition comprises: sending the physical layer packet to the receive end device, so that the receive end device determines two same consecutive target four-signal-segments in the first signaling field. generating a physical layer packet of a first protocol version of a wireless local area network, wherein the physical layer packet comprises a preamble, the preamble comprises at least a legacy preamble that complies with a second protocol version of the wireless local area network and a first signaling field following the legacy preamble, the first signaling field comprises at least two OFDM symbols, the first two OFDM symbols of the first signaling field each comprises five signal segments, and duration of each signal segment is 0.8 microseconds; and five signal segments of a first OFDM symbol are respectively a fourth signal segment, a first signal segment, a second signal segment, a third signal segment, and the fourth signal segment in sequence; and sending the physical layer packet to a receive end device, so that the receive end device performs recognition, characterized in that the first protocol version is a version of an 802.11ax device, the second protocol version is an earlier protocol version than the first protocol version and five signal segments of a second OFDM symbol are respectively the first signal segment, the second signal segment, the third signal segment, the fourth signal segment, and the first signal segment in sequence, wherein the sending the physical layer packet to a receive end device, so that the receive end device performs recognition comprises: sending the physical layer packet to the receive end device, so that the receive end device determines two same consecutive target four-signal-segments in the first signaling field. sending the physical layer packet to the receive end device, so that the receive end device determines two same consecutive target four-signal-segments in the first signaling field.