Abstract: Aiming at the pebble bed channels with internal heat source for heating transfer,this paper adopts the electromagnetic induction heating method to separately heat the pebble-bed composed of 3 mm and 8 mm diameter oxidized stainless steel balls and to study the internal heat transfer characteristics.By comparing and analyzing the experimental data,the changing of power distribution and heat transfer coefficient with the heat flux density,particle diameter and Re number of working fluid in the pebble bed channels is obtained,and is fitted to get the dimensionless correlation criteria of the average heat transfer coefficient.The fitting results accord well with the experimental results,and the error is within 15%.