Pronunciation is an important part of English learning. Vowel pronunciation, in particular, is an obstacle that learners often encounter. Various literature and experiments have suggested that when Chinese students learn English, they often make pronunciation deviations or errors because of the differences between their native vowels and English vowel pronunciation. Therefore, it is of far-reaching significance to study the influence of the position of stress in words on the pronunciation of English vowels. The purpose of this study is to explore the influence of the position of stress in words on the pronunciation of English vowels, and to apply the results to the acquisition of English pronunciation by Chinese students. Through data and information analysis, a method is expected to be found to improve the quality of English pronunciation acquisition, and provide theoretical and practical support for English teaching. The results of this study show that the stress position in a word has a certain influence on the pronunciation of English vowels, and the pronunciation of vowels in different positions is obviously different, through which practical suggestions for Chinese students' English pronunciation acquisition can be provided, such as more targeted training for different vowel pronunciation.