As a distributed energy technology, hybrid solar-fossil fuel energy system (HS-FFES) has characteristics not only in the hybrid utilization of the renewable and conventional energy, but also in the efficient storage of thermal energy. The HS-FFES system obtains outstanding performance in upgrading solar heat to high-grade solar fuel and storing thermochemical energy with high energy density. However, investigations on the dynamic behaviors are inadequate. This paper constructs a dynamic model including the thermal inertia, reaction kinetics and turbomachinery rotational inertia. Then, the design/off-design working condition properties are presented to show the non-linearity of this system. Last, several typical day scenarios under different building types, seasons and cities were simulated. Simulation results show that the proposed HS-FFES can reach high efficiency with energy saving rate above 35 percent.