Music theorist A.M.T.S. Boëthius in the Middle Ages believed that music occupied an important position in Quadrivium and closely correlated with morality and knowledge. He devoted his whole life to preserving and instructing ancient Greece culture as possible as he could, and propagated ancient records to later generations. Boëthius not only indefatigably debated and speculated on Greece philosophy, but also regarded the relationship between human and the universe as the focal point in his doctrine. He thought that the procedure of understanding the theory of world monism and God’s creation was to begin with learning the base and definition of Mathematics, then Geometry, Music, and the last Astronomy. Besides, Boëthius’ music thinking of holistic education was represented in his first category of writing: De institutione musica. Except approving music’s function of morality, in this work, the issue of “three level of music”, “who is a real musician” and “three level of music action” clearly illustrate Boëthius’ points which regard music as a mirror that reflects the universal order and consider music as a notion that leads to comprehending the tenet of whole creation and represents all great truth.