Unhealthy eating behaviors among Chinese schoolchildren are an important factor contributing to the rising incidence of childhood obesity and diet-related chronic diseases. These trends underscore the pressing need for practical, sustainable, and locally relevant interventions. This study uses Wuxing District, Huzhou City, Zhejiang Province, as a representative urban case to explore how school food systems, family environments, and institutional structures jointly influence children's eating habits and nutrition awareness. Using the Systemic Design approach, this study conducted a comprehensive diagnosis of the current food education and meal supply system in local schools and outlined the interactions between key stakeholders (students, parents, educators, food suppliers, and policy managers), revealing the systematic gap between nutrition knowledge and actual practice, as well as institutional and cultural barriers that hinder the formation of healthy habits.