Based on the relevant theories of cognitive psychology, this paper aims to explore and summarize the specific design principles and strategies of conversational interaction in the design direction of user cognitive needs. Based on the user behavior differences and cognitive characteristics, user interface design problems of cognitive process are analyzed, the user interface feeling and aesthetic, attention, learning and memory, and thinking characteristics demand are put forward, behavioral differences between explicit and non-explicit product users are combined, and cteristics - conversational interface mapping model experience requirements" is established. Through the analysis of cognitive characteristics and interactive interface experience demand of shopping chatbot, this paper puts forward corresponding interface design strategies from four aspects of user's feeling characteristics and aesthetic experience, attention characteristics, learning and memory characteristics, and thinking characteristics. Combined with the micro network system of information architecture, according to the three aspects of information integrity, information association and information entity, the proposed design strategy is sorted out, and the chatbot conversational interface design model is constructed from four levels of design requirements, cognitive requirements, interface design requirements, and design strategy.