The integrated energy system includes various energy forms, complex operation modes and tight coupling links, which bring challenges to its steady-state modeling and steady-state power flow calculation. In order to study the steady-state characteristics of the integrated energy system, the topological structure of the cold-thermal-electric integrated energy system is given firstly. Then, the steady-state model of the power subsystem, the thermal subsystem, the cold subsystem and the distributed energy station are established, the unified power flow model is established, and the Newton Raphson algorithm is used to solve the unified power flow model. Finally, the influence of the key technical parameters on the steady-state power flow of the integrated energy system is analyzed. Research results show that the photovoltaic power generation plays a supporting role in the voltage of each bus; with the increase of electric load power, the unit value of bus voltage decreases continuously; the water supply temperature of the source node has a greater impact on the steady-state flow in the pipeline and the water supply temperature of each node; the pipeline length of the heat network has a greater impact on the end temperature of the pipeline, the water supply temperature, and the return water temperature of each node. The analysis results can support the planning, design, and optimal operation of the integrated energy system.