This study aimed to systematically examine the impact of metacognitive strategy training on Chinese EFL (English as a Foreign Language) majors’ foreign language learning anxiety (FLLA) and to explore the underlying mechanism. A one-semester quasi-experimental intervention was conducted with 35 English-major university students using a single-group pretest–posttest design. Paired-samples t-tests and partial least squares structural equation modeling (PLS-SEM) were employed for data analysis. The results indicate that the intervention not only significantly reduced students’ FLLA levels but also increased their overall use of metacognitive strategies. The SEM analysis further revealed that time management, reflective learning, self-regulation, emotional regulation, and planning strategies were all significant negative predictors of FLLA, with time management showing the strongest effect. This study confirms that systematically cultivating students’ metacognitive strategies is an effective approach to alleviate foreign language learning anxiety. It provides empirical evidence and practical guidance for foreign language teaching aimed at reducing learner anxiety and promoting learner autonomy.