Birch Tree is one of the best nature poems written by Frost. This is also a Kubinashi rhyme poem, which well embodies the poet's exposition that "poetry begins with joy and ends with wisdom". This poem begins with a wonderful description of the birch tree and ends with a wise saying. People need to fantasize, but they will eventually come back to reality. In this poem, the poet looks at the birch tree, as if he saw a little boy holding the branches and swinging into the air. He recalled the joy of carefree play in his childhood; At the same time, I feel the complexity of the adult world and the hardships of life. He learned from the little boy's play when he swung off the ground and returned to the ground: people need fantasy and entertainment, but they can't escape from reality forever and live in fantasy. On the contrary, they should gain a foothold in reality, try to control reality and strike a balance between reality and fantasy.