Microturbine is one of core devices of small distributed energy supply system. In order to analyze the dynamic characteristics of adjustable regenerative microturbine, a mathematical dynamic model has been established by the modular modeling method. Multi-segment lumped parameter model of regenerator with distributed parameter's characteristics has been established. The compared result indicated that three-segment lumped parameter model is a reasonable method to satisfy the requirement of precision and easy calculation. The mathematical model above-mentioned was simulated and calculated on Matlab/Simulink simulation platform and a series simulation tests were performed with the major control variables (fuel input, the quantity of bypass flue gas) step disturbance. The simulation results show that the energy storage of regeneration's wall temperature and the quantity of regenerative flue gas has significant influences on microturbine's dynamic characteristics. The work has important reference value to the optimization of dynamic performance and the control design of the similar unit and its cogeneration system.