Vocabulary knowledge plays a fundamental role in English language learning，as it directly influences learners’ listening，speaking，reading， and writing abilities. However，many English as a Foreign Language （EFL） learners encounter persistent difficulties in vocabulary acquisition，such as limited retention，lack of contextual understanding，and low motivation. With the rapid development of artificial intelligence （AI），new opportunities have emerged to address these challenges in vocabulary teaching. AI-assisted tools are able to provide personalized learning content，immediate feedback，and flexible learning environments. This paper aims to explore the application of artificial intelligence in English vocabulary teaching by reviewing relevant literature and discussing practical instructional applications. The study examines how AI supports vocabulary presentation，practice，review，and learner autonomy. In addition，the advantages and challenges of AI-assisted vocabulary instruction are discussed. The findings suggest that AI has considerable potential to enhance vocabulary learning efficiency and learner engagement when integrated appropriately into English instruction.