Energy Internet has become a powerful driving force of energy production and consumption revolution allover China. Two core technologies, including smart micro grid and multi-energy complementary, are widely integrated into micro energy Internet. Energy sources, loads and storages of various energy forms are constructed and integrated as a whole, which imply complicated energy conversion, transmission mechanism and complex operation characteristics. However, the existing simulation means of various energy systems always only aim at one independent energy system, thus they cannot be directly applied to the coupling and interaction mechanism of different energy forms, or to the analysis of operation and control characteristics of multi-energy system. This paper has summarized the current development and achievement of simulations of micro-grids and other types of energy systems, which are the foundations of multi-energy system simulation. Then it has analyzed and summarized the basic characteristics of multi-energy system, intricacies and main points to implement its simulation. Furthermore, phased and multi-mode hybrid simulation is designed and presented with its key techniques. By the hybrid simulation, it is expected to make full use of the foundations of the existing energy equipment-system simulation models and algorithms and to establish dynamic and transient simulation of multi-energy system. The application of the phased and multi-mode hybrid simulation in the multi energy system is illustrated by a typical example of cold combined heat and power system.