Under the new format and business model of integrated energy services，basic research on integrated energy system modeling and physical mechanism analysis is particularly important. This paper first analyzes the domestic and international research status and development trends of the integrated energy system in terms of modeling and analysis，and then expounds the research system of energy network theory and method for modeling and analysis of integrated energy systems，including “unified modeling of integrated energy systems theory” and “analysis of dynamic behavior of energy and helium in integrated energy systems”，and analyzes the key scientific issues，and then gives specific research plans，and puts forward the core method of “modeling and physical mechanism analysis”. In the end，the research on energy network theory elaborates on how to establish a perfect energy network theory，realizes unified modeling of multi-energy systems，and introduces exergy and entransy to describe the characteristics of integrated energy systems. The challenges faced are analyzed and the prospect is presented.