The penetration rate of AI customer service in the cross-border e-commerce sector has been rising steadily. Evolving from simple early Q&A robots, it is now capable of intelligent Q&A and automated processing, real-time multilingual translation and cultural adaptation, as well as customer behavior and emotional analysis. AI and human customer service are not in a substitutive relationship but a collaborative and symbiotic one. The application of AI customer service in cross-border e-commerce is a continuous optimization process, which requires constant improvement in AI’s natural language understanding, regular update and refinement of the knowledge base, enhancement of AI’s capabilities in emotional recognition and personalized service, clear definition of the boundary and transfer mechanism of human-machine collaboration, and at the same time, promotion of system integration and data interconnection and sharing.