An audio data transmission method includes encapsulating, based on a physical layer frame header, a protocol data unit (PDU) including audio data, to obtain an audio data packet, where the physical layer frame header is modulated using a first digital modulation scheme, the PDU is modulated using a second digital modulation scheme, a value of a modulation rate of the first digital modulation scheme is equal to a value of a data transmission rate, and a value of a modulation rate of the second digital modulation scheme is less than the value of the data transmission rate, and sending the audio data packet on a BLUETOOTH low energy (BLE) physical channel at the data transmission rate.