Abstract: In order to improve the nuclear boiling heat transfer,a multi-scale porous surface was prepared by sintering the copper particles.A series of pool boiling experiments on different heater surfaces were conducted using deionized water as working fluid at atmospheric pressure.The effects of surface structure,liquid temperature,heat flux and surface superheat on the pool boiling heat transfer were investigated.The results showed that the multi-scale surface can perfectly meet the different demands for pore size between vapor release and liquid suction.For multi-scale surface,The surface superheat at the onset of nuclear boiling was decreased significantly and heat flux was expanded.Compared to that of a plain surface,the boiling heat transfer coefficient can be improved 5 to 6 times.