A signal sending method includes: generating a MAC CE indicating a power headroom in a first power headroom set or a power headroom in a second power headroom set; and if the MAC CE indicates the power headroom in the first power headroom set, the MAC CE includes a first bit field and a second bit field, the first bit field is a reserved bit field, and the second bit field indicates the power headroom in the first power headroom set; or if the MAC CE indicates the power headroom in the second power headroom set, the MAC CE includes a third bit field, the third bit field is used to indicate the power headroom in the second power headroom set, and the third bit field includes a bit of the first bit field and a bit of the second bit field; and sending the MAC CE to a network device.