The　use　of　renewable　energy　is　an　important　technical　way　to　achieve　building　energy　conservation　and　environmental　protection.　In　this　study,　a　new　type　of　dual-source　building　energy　supply　system　with　heat　pumps　and　energy　storage,　which　can　solve　the　problems　of　unstable　operation　and　low　reliability　of　a　single-energy　system　and　high　investment　and　operation　cost　of　existing　multi-source　energy　systems,　is　proposed.　In　this　system,　photovoltaic-thermal　water　is　used　as　the　low-temperature　heat　source　of　the　water　source　heat　pump　and　the　air　source　heat　pump　as　the　auxiliary　energy　supply　device　to　realize　cascade　utilization　of　energy.　＂Peak　load　shifting＂　and　minimization　of　building　energy　consumption　and　operation　costs　are　realized　by　storing　energy　(cold　and　heat)　at　night　when　electricity　prices　are　low.　On　the　basis　of　the　long-term　monitoring　data　of　the　energy　supply　system　for　an　office　building,　load-forecasting　and　system　performance　models　are　established,　and　the　operation　strategy　in　winter　and　summer　is　optimized.　Then,　the　whole-year　operation　of　the　system　is　simulated　and　analyzed.　Results　show　that　the　optimized　system　runs　efficiently　and　can　save　approximately　10%　of　operating　costs　compared　with　the　situation　before　optimization.　The　operating　cost　of　the　system　is　55%　of　that　of　the　conventional　air　source　heat　pump　system,　and　its　dynamic　payback　period　is　3.66　years.　The　proposed　system　is　a　form　of　building　energy　supply　system　worthy　of　popularization　and　application　in　cold　regions.