Accompanied by the innovation of artificial intelligence technology, robots as intelligent companion products are increasingly being used in interactions with people. With the goal of improving the emotional interaction experience between users and companion robots, this article innovatively integrates the theory of role identity into the interaction design research of companion robots and explores a robot interaction design strategy based on role identity. Firstly, the theory and formation mechanism of role identity in the field of human-robot interaction are analyzed, and the positive influence of role identity on human-robot interaction experience is verified. Secondly, perceived warmth is used as a mediator to connect role identity and user interaction experience, and the interaction design elements affecting the role identity of intelligent companion robots are explored from three layers of emotional design: the instinctive layer focuses on the design elements of the audio-visual channel; the behavioral layer focuses on feedback time and interaction mode; and the reflective layer centers on the establishment of the role relationship, deducing the design decisions for the instinctive and behavioral layers in reverse. A set of role identity-based interaction design methodologies for companion robots is finally proposed and evaluated through design practice. The evaluation employs comparative experiments, and the results show that the optimized design companion robot significantly enhances the user’s role identity and interaction experience, verifying the feasibility of the design strategy, which holds certain academic value and practical significance.