Abstract: Heat storage based on metal oxide can be combined with solar air Brayton power generation system, which can achieve high quality power generation and fast peak and frequency regulation. In order to meet the operational regulation requirements of the air Brayton power generation system for the heat storage device, a numerical model of the heat storage device which couples flow and heat exchange with chemical reaction is constructed, and the maximum relative error between simulation and experimental results does not exceed 6.2%. Based on the numerical model, the numerical simulation of a manganese metal oxide heat storage device is carried out, and the results show that the isotherm line and the iso-reaction rate line are both parabolic, the temperature curves at different positions display "plateau" areas in the reduction and oxidation reaction temperature range, and the height and length of the areas are affected by the rate of temperature rise and fall. Compared to the pure sensible heat storage section, the total heat storage capacity of the thermochemical heat storage device has increased by 61.4%. The results of the study can provide a reference for the design and operation regulation of metal oxide heat storage devices in solar air Brayton power systems.