Among Su Shi's numerous literary theories, the theory of "small three and unity" is the most refined summary and the most prominent reflection of his conscious pursuit of reason and interest and old beauty in literary and artistic creation. This view of literary theory was first put forward in the article After Huang Zisi's Poems: "The quality of books is called the trace of the king of bells, and the beauty lies in the fact that it is simple and far away. Arrived, Liu, the ancient and modern brushwork was collected and published, and the change of calligraphy style made the world feel like a master. However, the legal benefits of Zhong and Wang are not great. As for poetry, the same is true. Su Zhi and Li Zhi are natural, Cao Zhi and Liu Zhi are complacent, Zhi Tao and xie zhi are extraordinary, and the cover is coming. Li Taibai and Du Zimei, with a peerless attitude, have crossed over a hundred generations, and all ancient and modern poets have been abolished; However, since the Wei and Jin Dynasties, it has been extremely dusty and rarely declined. After Li and Du, the poet continued to write. Although there was a long rhythm between them, he didn't understand it. Wei and Liu Zongyuan are unique, but they are sent to indifference, which is beyond our reach. At the end of the Tang Dynasty, Si Kongtu was rough and chaotic, but his poems were elegant, and he still had a peaceful legacy. His poem says:' Plum stops at acid and salt stops at Yu Xian. You can't eat plums without salt, but its beauty often exceeds salty and sour.' Gai cited twenty-four rhymes of his poems to express them in words, hating that he didn't know the mystery at that time, so he repeated his words and was sad. ..... Believe it or not, beauty is beyond salty and sour, with three sighs. Taking calligraphy as a metaphor, this paper comments on poetry, and points out that good poetry contains profound artistic conception in prosaic. We admire the "natural beauty" of Su and Li, the "complacency" of Cao and Liu, the "detachment" of Tao and Xie, the talents of Li and Du, and the "indifference and elegance" of Liu Zongyuan and Wei. Especially for nature, "beauty is beyond salty and sour" poems, it is even more admired. As a matter of fact, the style of "Little Three Build Yuan" runs through Su Shi's literary works, which contains his views on the relationship between words and meaning, form and god.