Wearable computing devices enable continuous sensing and real-time processing of both the human body and its surrounding environment, offering intelligent interactive services anytime, anywhere. This chapter explores the multimodal interaction of wearable devices in the context of human-artificial intelligent (AI) interaction. It outlines the design principles and goals of HCAI intelligent wearable interaction, providing guidance for the development of wearable technology. The chapter presents an in-depth analysis of the sensors that support intelligent interaction, detailing their types, principles, and applications. Key interaction modalities such as finger touch, hand and head movements, and eye tracking are examined to demonstrate how wearable devices enhance user experiences and contribute to the development of HCAI AI (HCAI) systems. The chapter concludes by addressing future challenges and opportunities in wearable computing interactions, providing readers with insights into design strategies, sensor technologies, and the latest research progress in intelligent wearable interaction.