A method for driving a digital speaker based on code conversion, successively comprising steps of: converting input signals into high-bit pulse code modulated, PCM, signals with a bit width of N and a sampling rate of fs; performing multi-bit ∑-Δ modulation to the high-bit PCM signals, to push the noise energy within an audio bandwidth out of the audio band; converting low-bit PCM signals having a bit-width of M bit and sampling rate of fo output by the ∑-Δ modulation step into 1-bit coded signals corresponding to 2 M transmission channels of a digital power amplifier and a speaker load by a thermometer code conversion, and distributing the 1-bit coded signals to 2 M digital channels in terms of equal weight, the digital signals of each channel only having two coding states of '0' and '1'; applying dynamic mismatch-shaping to the binary status code vectors of 2 M channels obtained by the thermometer code conversion based on the binary status codes of '0' and '1', to eliminate harmonic distortion components arisen from a frequency response difference between post-stage digital-to-analog conversion loads of 2 M channels and reduce the noise amplitude; converting pulse density modulation, PDM, coded signals with a high switching rate of each channel obtained after said multi-bit Σ - Δ modulation and dynamic mismatch-shaping into pulse width modulation, PWM, coded signals with a low switching rate; and controlling the on/off status switching of a full-bridge power amplification network to drive a digital speaker load sound, wherein each two half-bridge channels drive one speaker unit to form said full-bridge power amplification network, one path of the PWM coded signals is output to an input end of one half-bridge channel, and the other path of the PWM coded signals is output inversely to an input end of the other half-bridge channel, such that differential PWM control signals are utilized to control the on/off action of four MOSFETs, thereby forming the current path of two switching states of '+1' and '-1'; further wherein when the on/off action of the full-bridge power amplification circuit is controlled by the binary status code of '0' and '1', provide that 'HA' and 'LA' respectively represent the reference numbers of the high-edge and low-edge MOSFETs at A side, and 'HB' and 'LB' respectively represent the reference numbers of the high-edge and low-edge MOSFETs at B side, when inputting at the state of '0', HA and LB being simultaneously turned on and HB and LA being simultaneously turned off, such that the current flows from A end to B end through the speaker unit and the voltage on the speaker unit is '+V CC ', and when inputting at the state of '1', HB and LA being simultaneously turned on and HA and LB being simultaneously turned off, such that the current flows from B end to A end through the speaker unit and the voltage on the speaker unit is '-V CC '. converting input signals into high-bit pulse code modulated, PCM, signals with a bit width of N and a sampling rate of fs; performing multi-bit ∑-Δ modulation to the high-bit PCM signals, to push the noise energy within an audio bandwidth out of the audio band; converting low-bit PCM signals having a bit-width of M bit and sampling rate of fo output by the ∑-Δ modulation step into 1-bit coded signals corresponding to 2 M transmission channels of a digital power amplifier and a speaker load by a thermometer code conversion, and distributing the 1-bit coded signals to 2 M digital channels in terms of equal weight, the digital signals of each channel only having two coding states of '0' and '1'; applying dynamic mismatch-shaping to the binary status code vectors of 2 M channels obtained by the thermometer code conversion based on the binary status codes of '0' and '1', to eliminate harmonic distortion components arisen from a frequency response difference between post-stage digital-to-analog conversion loads of 2 M channels and reduce the noise amplitude; converting pulse density modulation, PDM, coded signals with a high switching rate of each channel obtained after said multi-bit Σ - Δ modulation and dynamic mismatch-shaping into pulse width modulation, PWM, coded signals with a low switching rate; and controlling the on/off status switching of a full-bridge power amplification network to drive a digital speaker load sound, wherein each two half-bridge channels drive one speaker unit to form said full-bridge power amplification network, one path of the PWM coded signals is output to an input end of one half-bridge channel, and the other path of the PWM coded signals is output inversely to an input end of the other half-bridge channel, such that differential PWM control signals are utilized to control the on/off action of four MOSFETs, thereby forming the current path of two switching states of '+1' and '-1';