The invention provides a song mode determining method, which comprises the steps of acquiring music score information of a song; acquiring the scale step in each mode; according to the scale step in each mode, determining natural notes in a note sequence corresponding to each mode of the song; according to the note sequence of the song and the duration of each note in the note sequence, determining the ratio of the natural notes in the note sequence corresponding to each mode of the song; and determining the mode corresponding to the maximum ratio of the natural notes as the mode of the song. The invention further provides a song mode determining device. The song mode determining method and the song mode determining device can determine the mode of the song according to the ratio of the natural notes in the note sequence of the song and correct the pitch according to the scale step in the corresponding mode; and the mode determining accuracy and the pitch correction accuracy are high.