The purpose is to avoid the contradiction of emotional subject changes in book design research, use the affect theory as the theoretical tool for emotional design research of paper books for the first time, and develop new ideas for the practical emotional book design. Based on the understanding of affect by Spinoza, Deleuze, Masumi, etc., the emotional sources and transmission process of books, the expression of emotions in book binding design, and the emotional communication in design were analyzed from three aspects:people, objects, and interaction between people and objects. The emotions contained in books are the result of the expression and transmission of emotions by multiple subjects such as authors, editors, designers, and readers. Designers should comprehensively use various emotional expression methods from a holistic perspective, highlight the intensity and changes of emotions, and help readers experience affect during the reading process.