Classical poetry is a kind of special classical literature with highly concise language, rich emotion, profound implication and certain rhythm. The development of poetry translation is related to the spread of Chinese classical culture. There are many opinions about translatability and Untranslatability of poetry translation. The translation of meaning is relatively easy, while the rhetoric technique closely related to the form of expression is more difficult, which is the key to express the poet's feelings. There?fore, this paper aims to explore the untranslatability of onomatopoeia in poetry by combining with the Book of Songs.