Abstract: With the acceleration of the energy transition process, the source-network-load-storage role of urban energy systems（UESs） will undergo a significant change, and the system morphology will evolve towards the direction of deep cyber-physical fusion and multi-energy partition interconnection. This trend not only provides more flexible resources for the UES operation, but also introduces a large number of complex uncertainties to the operation regulation, which greatly restricts the safe, economic and sustainable development of the UES. Based on the analysis of morphology evolution of the UES in the energy transition process,this paper expounds the morphological characteristics of future partition interconnection of the UES, and analyzes the challenges faced by the operation regulation of the UES in the new morphology. Furthermore, the key technologies of the operation regulation of the UES are discussed from four aspects, including complementary potential analysis, operation situation awareness, flexible interconnection control, reliability assessment and resilience improvement. And the research direction of related technical problems is prospected.