Abstract: Secondary water supply is an important part of municipal pipe networks, directly impacting drinking water quality for thousands of households. To meet the requirements of the new situation and strengthen the sanitary management of secondary water supply facilities, the Beijing Center for Disease Prevention and Control ‌led the revision of‌ the Hygienic Specification for Facilities of Secondary Water Supply (GB 17051—1997) from 2020 to 2025. The revised standard, Hygienic Specification for Facilities of Secondary Water Supply (GB 17051—2025), was issued on May 30, 2025, and will be implemented on June 1, 2026. This article interprets the background, drafting principles, main concepts, and main contents of the revision, thus improving the understanding about the contents of the standard and guide the application of the standard.