The work aims to explore the design of intergenerational interactive toys from the perspective of peer learning in order to stimulate the high-quality development of family education and promote the mental health of the younger elderly and preschool children. The concept and development trend of peer learning theory and its application in product design were summarized. The feasibility and positive significance of introducing peer learning theory into intergenerational interactive toy design were investigated. Based on the user behavior analysis the intergenerational grandparent-child interaction needs were summarized from three aspects of product, user and environment and a theoretical model of intergenerational peer learning was proposed to guide design practice. The theoretical model of peer learning between generations is proposed in view of the current situation of intergenerational interaction and the peer learning theory. This multi-generational design might ease the imbalance of generations and promote the cognitive complementation between grandparents and grandchildren in order to guide the two sides to carry out peer learning interaction. The effectiveness and scientificity of the theoretical model are verified through design practice and the differences between generations will be transformed into peer learning driving force through edutainment to build a multiple intelligence promotion platform and emotional communication channel for both sides.