This article explores the application of a cognitive linguistic approach in teaching Vietnamese idioms to foreign learners, emphasizing the role of conceptual metaphors. The study demonstrates how understanding the underlying metaphorical structures can enhance learners' comprehension, retention, and application of idioms in practical contexts. By employing various cognitive-based teaching strategies, learners develop the ability to recognize and use idioms more flexibly and accurately. After applying this approach, the findings reveal significant improvements in learners’ interest, synthesis thinking, and strategic use of language. The research underscores the potential for extending cognitive methods to other areas of language teaching for comprehensive skill development.