Disclosed are a data-packet preamble sequence and a method for processing a packet header, comprising the following steps: the sync field of the preamble sequence uses a fixed-mode bit sequence in place of a scrambled pseudo-random bit sequence, and uses Barker code spreading; the spread code length is extended to spread the spectrum of the SFD field in the preamble sequence; the spread code length is extended to spread the spectrum of the packet header field. The present invention is capable of significantly improving the detection receiving performance of the preamble sequence (sync field and SFD field) and the PLCP packet header field; long-distance channel conditions can be better withstood, enhancing the stability of signal transmission; it is also simple to implement and requires only that the circuit of an existing Wi-Fi device be slightly modified.
