The work aims to propose an optimized FBS model to improve the influence of user factors on decision-making in the design process, thus achieving the resonance of user needs and design model. Different from a purely data-oriented analysis method, a reasonable FBS model was used to determine the main framework of design research and analyze users with empathy concepts. The behavior and psychological characteristics of users were adopted to guide experiment and explore and import their potential needs into the FBS model framework for design, so that the design process achieved a combination of rational factors and perceptual factors. With shared children's positioning equipment as an example, design experiment was carried out in combination with the characteristics of shared facilities involving multiple user groups. Simple operation methods were used to explore new design points. The process included complete user analysis, product design and usability evaluation, which could be used to improve design efficiency and deepen the connection among users, products and environment. The experimental results reveal that the improved method can improve the user experience more clearly and effectively, and provide ideas for the research of design need analysis methods.