As high-energy-consuming public buildings and medical institutions, hospitals hold profound significance for the realization of China’s “dual carbon” goals through their energy management. Taking pediatric wards as the research object, this study constructed a three-dimensional collaborative intervention model of “institutional level—equipment level—behavioral level” targeting their energy consumption characteristics (dense wards, high accompanying rate, and continuous operation of medical equipment). Through a stepped controlled trial design (self-control during 2024—2025 and spatial control with gynecological wards), this study systematically evaluated the implementation effect of energy-saving measures. The research results show that after the implementation of intervention measures, the monthly average electricity savings in pediatric wards exceeded 900 kWh, with an average electricity saving rate of 21.36%. Through difference analysis, the impact of external environments was excluded, verifying the effectiveness of the three-dimensional collaborative mechanism. This study provides a comprehensive “technology-management-behavior” energy-saving path for medical institutions, which has high promotion value.