With the rapid development of artificial intelligence technology, large language models have gradually penetrated into the field of education, bringing innovative changes to English vocabulary teaching. DeepSeek, as an advanced large language model, has the advantages of strong contextual understanding, personalized interaction, and efficient information processing, which provides new possibilities for solving the problems existing in traditional English vocabulary teaching, such as single teaching method, low learning efficiency, and lack of personalized guidance. This paper takes the application of DeepSeek in English vocabulary teaching as the research object, adopts the methods of literature research, questionnaire survey and experimental research to explore the application path, effectiveness and existing problems of DeepSeek in English vocabulary teaching. The research results show that DeepSeek can effectively optimize the teaching process of English vocabulary, improve students' learning interest and vocabulary mastery, and alleviate the teaching burden of teachers. However, there are still some problems in practical application, such as insufficient integration with teaching objectives, uneven quality of generated teaching resources, and potential risks of data privacy. Based on this, this paper puts forward corresponding optimization strategies to provide theoretical support and practical reference for the integration of DeepSeek and English vocabulary teaching. Finally, the research prospects are prospected, hoping to promote the in-depth development of intelligent English vocabulary teaching.