In order to analyze the unsteady heat transfer characteristics of solar porous media power tower receiver,first,unsteady heat transfer models are established.Then,a volumetric convective heat transfer coefficient model suitable for the receiver is proposed based on the least squares method.Finally,the models are solved by numerical method to analyze the typical unsteady dimensionless temperature field,and to further reveal the influences of the average particle diameter,the porosity,the thickness and the air inlet velocity on the unsteady dimensionless temperature distribution.The results show that porous media with small particles,low porosity,low thickness and high air inlet velocity benefit the reduction of thermal stress-induced destruction.