Western poetry is widely accepted for its unique romance,and many famous poets have emerged since then.Yeats is a famous Irish poet;he led the Irish Renaissance movement,who is a romantic poet with patriotic feelings.He wrote numerous works during his lifetime,including When You Are Old,which has influenced generations and pushed traditional poetry to modernism.This paper will analyze the three translated versions under the guidance of Xu Yuanchong’s famous“Three Beauties Theory”,in order to explore the application and deficiency of“Three Beauties Theory”in poetry translation and promote the progress of translation studies.