A method and a device for adjusting an audio signal, and an audio system are provided. The method includes: obtaining a candidate audio signal (S1); obtaining a current noise signal in an environment (S2); calculating a first plurality of difference values in loudness between the candidate audio signal and the current noise signal (S3); modifying the first plurality of difference values with a plurality of target factors, where the plurality of target factors are obtained based on a plurality of test noise signals and a corresponding plurality of test audio signals (S4); and modifying the candidate audio signal with the modified first plurality of difference values to obtain a target audio signal (S5). Therefore, loudness loss of the audio signal perceived due to the noise signal can be compensated, and an overcompensation issue can be solved.