The word “root” originally refers to the root of a tree, and it mostly refers to the fundamental intent. This word is an important image in the ancient Yi poetic theory. Since the Wei, Jin and southern and Northern Dynasties, Yi poetry theorists often use the "root" to express their poetic ideas. Amani is a great Bimo, a poetess in the ancient Wei and Jin Dynasties, and one of the founders of Yi ancient poetics. In her book On the Poetic Laws of Yi Language, she used the image of "root" to construct the aesthetic system and express her poetic ideas. The purpose of this paper is to explore the function and significance of the "root" image in the theory of Yi language poetry by the ancient Yi literary theorist Amani through the method of image criticism.