The development of libraries in the Artificial Intelligence (AI) age requires a rethinking of their mission and services. This article introduces the concept of a "Smart Affective Library," aimed at bridging the gap between traditional resource repositories and the evolving needs of modern learners. By delving into three core elements of libraries -information, interpersonal interaction, and space design, public libraries in the AI age are reset to integrate of learning modes, cognitive processes, and affective states for readers. On various service designs responsive to readers' cognition and sensory experiences, the libraries introduce diverse services based on mixed-reality environment, and through filtering multiple categories of affective information. This will stimulate a more effective and emotionally resonant learning experience for readers, increase their engagement, and transform the library into a dynamic space for knowledge co-creation.