Abstract: Thermal energy storage is necessary for improving energy utilization efficiency. Using Ca(OH)2/CaO in fluidized bed reactors can realize rapid storage and release large-scale thermal energy, and hence, research on the reaction kinetics of Ca(OH)2/CaO under fluidization is important. However, the thermogravimetric analysis (TGA) technique cannot provide the constant temperature reaction conditions required for Ca(OH)2, and its mass transfer inhibition phenomenon is significant. Hence, a fast-reaction TGA technique was proposed that can provide reaction conditions closer to those of fluidization for Ca(OH)2/CaO, when compared with the conventional TGA technique. The fast-reaction TGA technique could provide a higher heating rate and better mass transfer conditions for heat storage material by rapidly moving the high-temperature reactor and introducing a high-speed purge gas. The influence of the reactor temperature, moving speed and airflow on the fast-reaction TGA performance was clarified by decoupling experiment. When tested with Ca(OH)2, the deviation in the material conversion obtained with the fast-reaction TGA technique from that obtained with the conventional TGA technique is only 0.81%, which demonstrates the accuracy of the fast-reaction TGA.