A wake-up packet sending method, including: obtaining, by a sending apparatus, a wake-up packet WUP, where the WUP includes a preamble sequence, and the preamble sequence includes N consecutive first sequences S, where N is an integer greater than or equal to 2 (for example, [S S]), and the N consecutive first sequences S are used to indicate that a data rate used for the WUP is a first value; or the preamble sequence includes a second sequence M, where the second sequence M is used to indicate that a data rate used for the WUP is a second value; and the second sequence M and the first sequence S are in a bit logical negation relationship; and sending the WUP, to wake up a main receiver of a receiving apparatus.