This study investigates and practices the auxiliary role of Artificial Intelligence (AI) technology, especially Large Language Models (LLM) and Text-to-Speech (TTS) technology, in English oral teaching. In the study, an AI-based LLM oral dialogue platform was constructed to replace teachers for one-on-one interactive training with students. It has been applied in college English teaching in various universities, and teaching data has been collected and analyzed in real-time. The effectiveness of AI technology in assisting college English oral teaching was evaluated, and the role of AI technology application in improving students' oral skills was explored. We conducted comparative analysis on indicators such as the speaking sentence length, speech rate, and combined with questionnaires from students, we surveyed the practical effects of AI oral teaching. The study shows that AI-assisted dialogue training has a significant positive effect on college English oral skills, and we have also proposed corresponding teaching strategies and suggestions.