Abstract: In response to the challenges faced by information construction in small and medium-sized irrigation districts, such as weak infrastructure, low collaboration levels, insufficient business empowerment, and lack of top-level design, this paper proposed a construction framework for a digital twin system in small and medium-sized irrigation districts, and conducted a preliminary discussion on the key technologies and implementation paths. Taking the medium-sized reservoir irrigation district of Muqiaogou in Sichuan Province as a research subject, a digital twin system for the irrigation district was constructed. The results showed that using this system for management achieved a gate response delay of less than 2 seconds, a water resource allocation simulation calculation time of less than 1 minute, and an 80% improvement in flood rehearsal efficiency. The digital twin system effectively supported water resource scheduling in the irrigation district, as well as engineering operation and management services. The results could provide a reference for similar projects.