A method of signal sending performed by a terminal device, comprising: generating a media access control, MAC, control element, CE, wherein the MAC CE is used to indicate a power headroom in a first power headroom set or a power headroom in a second power headroom set; sending the MAC CE to a network device; and indicating the used power headroom set to the network device, wherein: if the MAC CE is used to indicate the power headroom in the first power headroom set, the MAC CE comprises a first bit field, a second bit field and a data volume field, the first bit field is a reserved bit field, and the second bit field is used to indicate the power headroom in the first power headroom set, and wherein the data volume field indicates a data volume; if the MAC CE is used to indicate the power headroom in the second power headroom set, the MAC CE comprises a third bit field and the data volume field, the third bit field is used to indicate the power headroom in the second power headroom set, the third bit field comprises all bits of the first bit field and all bits of the second bit field, and a number of power headroom levels in the second power headroom set is greater than a number of power headroom levels in the first power headroom set. generating a media access control, MAC, control element, CE, wherein the MAC CE is used to indicate a power headroom in a first power headroom set or a power headroom in a second power headroom set; sending the MAC CE to a network device; and indicating the used power headroom set to the network device, wherein: if the MAC CE is used to indicate the power headroom in the first power headroom set, the MAC CE comprises a first bit field, a second bit field and a data volume field, the first bit field is a reserved bit field, and the second bit field is used to indicate the power headroom in the first power headroom set, and wherein the data volume field indicates a data volume; if the MAC CE is used to indicate the power headroom in the second power headroom set, the MAC CE comprises a third bit field and the data volume field, the third bit field is used to indicate the power headroom in the second power headroom set, the third bit field comprises all bits of the first bit field and all bits of the second bit field, and a number of power headroom levels in the second power headroom set is greater than a number of power headroom levels in the first power headroom set. if the MAC CE is used to indicate the power headroom in the first power headroom set, the MAC CE comprises a first bit field, a second bit field and a data volume field, the first bit field is a reserved bit field, and the second bit field is used to indicate the power headroom in the first power headroom set, and wherein the data volume field indicates a data volume; if the MAC CE is used to indicate the power headroom in the second power headroom set, the MAC CE comprises a third bit field and the data volume field, the third bit field is used to indicate the power headroom in the second power headroom set, the third bit field comprises all bits of the first bit field and all bits of the second bit field, and a number of power headroom levels in the second power headroom set is greater than a number of power headroom levels in the first power headroom set.