Abstract: In order to better understand the dynamic characteristics of the dual-pressure natural-circulation gas turbine heat recovery steam generator, the lumped parameter method is used in this article to build a dynamic simulation model of a dual-pressure natural-circulation gas turbine heat recovery steam generator in Matlab/Simulink according to the principle and structural characteristics of the boiler, with the tube bank heat transfer in full consideration. The dynamic response characteristics of the main parameters are simulated with 10% perturbation of engine exhaust gas flow and its temperature, and the high-pressure feeding water flow. The results indicate that the engine exhaust gas temperature influences the steam parameters the most, the exhaust gas flow has less effect on them, high-pressure feeding water flow the least. The simulation results fit the practical operation data well, meaning that the model has high precision and good versatility, and can provide a reasonable technical reference for the same type boilers on thermal operation.