The present invention discloses a method and an apparatus for earphone sound effect compensation and an earphone. The method of the present invention comprises: obtaining monitored signal data in a current wearing state of an earphone user according to a signal collected by a monitoring microphone and an audio signal played by a loudspeaker of the earphone; computing error data of the monitored signal data in the current wearing state relative to standard signal data in a standard wearing state of the earphone; and performing sound effect compensation to the earphone according to the error data. The technical solution of the present invention adopts an adaptive digital signal processing manner, which can dynamically compensate for sound effects in different earphone wearing manners and enable an earphone user to appreciate an audible effect in a standard earphone wearing state.