A coding method, comprising the following steps performed by a coding apparatus: coding a low frequency band signal of an input audio signal to obtain a characteristic factor of the input audio signal, wherein the low frequency band signal corresponds to a first frequency range of the input audio signal; performing coding and spread spectrum prediction on a high frequency band signal of the input audio signal to obtain a first full band signal, wherein the high frequency band signal corresponds to a second frequency range of the input audio signal; coding the high frequency band signal of the input audio signal to obtain high frequency band coding information; performing de-emphasis processing on the first full band signal, wherein a de-emphasis parameter of the de-emphasis processing is determined according to the characteristic factor; calculating a first energy of the first full band signal that has undergone de-emphasis processing; performing band-pass filtering processing on the input audio signal to obtain a band-pass filtered second full band signal, wherein the band-pass filtered second full band signal corresponds to a third frequency range of the input audio signal, and wherein the second frequency range covers a frequency range from the highest frequency of the first frequency range to the lowest frequency of the third frequency range; calculating a second energy of the band-pass filtered second full band signal; calculating an energy ratio of the second energy of the band-pass filtered second full band signal to the first energy of the first full band signal; and sending to a decoding apparatus, a bitstream including the characteristic factor, the high frequency band coding information, and the energy ratio. coding a low frequency band signal of an input audio signal to obtain a characteristic factor of the input audio signal, wherein the low frequency band signal corresponds to a first frequency range of the input audio signal; performing coding and spread spectrum prediction on a high frequency band signal of the input audio signal to obtain a first full band signal, wherein the high frequency band signal corresponds to a second frequency range of the input audio signal; coding the high frequency band signal of the input audio signal to obtain high frequency band coding information; performing de-emphasis processing on the first full band signal, wherein a de-emphasis parameter of the de-emphasis processing is determined according to the characteristic factor; calculating a first energy of the first full band signal that has undergone de-emphasis processing; performing band-pass filtering processing on the input audio signal to obtain a band-pass filtered second full band signal, wherein the band-pass filtered second full band signal corresponds to a third frequency range of the input audio signal, and wherein the second frequency range covers a frequency range from the highest frequency of the first frequency range to the lowest frequency of the third frequency range; wherein the band-pass filtered second full band signal corresponds to a third frequency range of the input audio signal, and wherein the second frequency range covers a frequency range from the highest frequency of the first frequency range to the lowest frequency of the third frequency range; calculating a second energy of the band-pass filtered second full band signal; calculating an energy ratio of the second energy of the band-pass filtered second full band signal to the first energy of the first full band signal; and sending to a decoding apparatus, a bitstream including the characteristic factor, the high frequency band coding information, and the energy ratio.