The present disclosure discloses an audio encoding and decoding method and an audio encoder and decoder. The audio encoding method includes: obtaining a current frame of an audio signal, where the current frame includes a high frequency band signal and a low frequency band signal; obtaining a first encoding parameter based on the high frequency band signal and the low frequency band signal; obtaining a second encoding parameter of the current frame based on the high frequency band signal, where the second encoding parameter includes tone component information; and performing bitstream multiplexing on the first encoding parameter and the second encoding parameter, to obtain an encoded bitstream.