Abstract: Z-pinch driven fusion-fission hybrid energy reactor (Z-FFR) is a new energy system, which is helpful to the sustainable development of nuclear energy. It runs in a pulsed mode with a period of 10s, in order to output a mean thermal power of 3000 MWt, a large quantity of energy has to be generated in a pulse. The transient heat transfer and temperature variation of the blanket and first wall in the strong heat shock situation are key issues to the technical feasibility of Z-FFR. In this paper, the temperature variation of blanket and first wall under consecutive heat pulse is analyzed through numerical simulation. Meanwhile, with the aim of exporting electric power stably, a simple method of stabilizing the output power is proposed, and the fluctuation character of the outflow in the main pipe is described. The results show that, the maximum temperatures of all materials are in the safety margin, the thickness of the layer that has a relative high temperature on the surface of the first wall is about 0.5 mm, the output power has a fluctuation of -2.84% to +2.05% relative to the nominal value.