Objective: Through literature analysis, this study preliminarily constructs core information items for water intake literacy among school-age children, providing a basis for enhancing the water intake literacy of school-age children in China. Method: Guided by the current status and issues of drinking behaviors among school-aged children, this study developed a preliminary conceptual framework and dimensions for core information on water intake literacy, followed by an evidence-based analysis to formulate initial items. It was based on literature searches and systematic evidence analysis, referenced international and domestic guidelines and standards for drinking water, and grounded in physiology and pathophysiology. The Delphi method was utilized to conduct two rounds of expert consultations with 11 specialists in relevant fields to ascertain the core items. Result: Following a literature-based analysis, preliminary core items for school-aged children's water intake literacy were proposed. Two rounds of Delphi consultations were executed via email, achieving a 100% active participation rate in both instances, with an average credibility score of 0.8409. The consensus among experts was notably high in both rounds, and the coefficients of agreement were statistically significant (P<0.01). Ultimately, 20 core information items were established, covering two domains: cognition and skills, as well as multiple dimensions, including knowledge of drinking water and healthy drinking, and skills for safe and healthy drinking. Conclusion: The Delphi method has facilitated the establishment of core information items for school-aged children's water intake literacy through expert consultation.