This paper discusses the phonological migration of the Mandarin vowel system to the American vowel system during second language acquisition. To this end, six Mandarin-speaking Chinese students who received English certificates are selected for analysis in this paper. In addition, experimental results from previous studies are utilized for further phonological comparisons, and a perception task and an articulation task are used to compare similar vowel combinations in the Chinese and English vowel systems. The perception task is designed to assess the participants' ability to distinguish similar vowels in different vowel systems, while the articulation task utilized Praat software to acoustically analyze the participants' vowel and word pronunciation, standard English pronunciation, and Chinese vowel pronunciation. The pronunciation values are compared with the standard pronunciation values, and the relationship between similarity and learning difficulty is established to test the hypotheses. The results shows that Chinese students are influenced by the Chinese vowel system and are unable to distinguish similar vowel combinations. Therefore, the higher the similarity between English vowels and Chinese vowels, the better the acquisition effect.