The rapid development of digital information technology provides new opportunities for the development of traditional children's picture books. Based on the research of children's cognition, the interactive design in children's picture books is innovated. Based on Piaget's cognitive theory of children, the research is carried out around the children aged 7-12 years old, and the characteristics of des-egocentricity, conservation and reversibility of children at this stage in terms of self-awareness, thinking mode and thinking ability are analyzed. The application effects and advantages of multi-symbol integrated visual design, multimodal application behavior design and multi-entertainment interactive derivative design in picture book design are proposed. Through the design practice of Playing with the 24 Solar Terms, from the three aspects of visual elements, behavioral elements and derivative elements, the design method is applied to achieve the reading needs of improving children's cognition, stimulating children's exploration and strengthening the integration of knowledge and action, so as to provide certain strategies for the design and development of interactive children's picture books of science and technology in the future. At the same time, it also provides practical reference for designers to create diversified interactive design.