Abstract: Metacognitive strategy is a learning method in which learners use cognition to process knowledge and adjust language learning through planning, monitoring and evaluation. Based on the theory of metacognitive strategy and current situation of college students' phonetic learning, this paper designs a 12-week empirical study on the teaching of metacognitive strategy among 60 first year English majors in Anhui University of Technology, and explores the practical teaching effect of metacognitive strategy theory in the production of four front vowels /i/、/I/、/e/、/æ/. Results show that metacognitive strategies can effectively improve the effect of phonetic teaching, and the positive effects on the correct production of front vowels are:/æ/ > /e/ > /i/ > /I/.