Accurately predicting and analyzing the dynamic coupling between the internal multi-physical processes and the external multi-heat transfer devices of solid oxide fuel cells (SOFCs) is the key to the high-performance operation of fuel cell systems and integration in distributed energy systems. Neither complex multidimensional simulation models nor simplified external characteristic models can achieve fast and accurate dynamic performance analysis of the SOFC system. This paper constructed a new cross-scale dynamic model of SOFC systems by using the standard thermal resistance method to analyze the external heat transfer subsystem and the equivalent circuit method to analyze the internal heat and mass transfer and electrochemical multi-physics coupling processes. The model realizes the overall cross-scale dynamic modeling of the SOFC system from the internal heat and mass transfer and electrochemical processes to the external heat exchange processes by using the characteristic parameters. The cross-scale dynamic model could be used for the holistic modeling of distributed energy systems including other energy conversion devices.