Abstract: In order to improve the energy utilization efficiency of microgrid with heat and power system, this paper established the multi-energy coupling conversion model and proposed an energy comprehensive utilization optimization method, which is based on the cascade utilization principle. We analyzed the structure of microgrid with heat and power system and established the cascade utilization process during the cold, heat and electric energy production. The relationship between source, demand and storage was also considered. According to different energy grades and their conversion modes, the energy flow coupling model and the energy grade conversion model were established to realize the energy exchange between electric energy and thermal energy and between different grades of thermal energy. The energy supply and demand model of different energy bus was built. Finally, based on the operational constraints of the energy cascade optimization utilization model, the optimal scheduling strategy of each equipment was solved with the goal of the lowest daily operating cost. Simulation shows that the proposed methodology effectively reduced the operating cost and improved the comprehensive energy utilization efficiency.