Abstract: A key joining technique between C/C composite and copper alloy heat sunk was shown.Firstly,the C/C surface was treated by pluse laser to form some grooves,then a thin layer of copper was casted with active metal,finally CuCrZr alloy was attached by brazing or electron beam welding.The numerical simulating results show that this kind of joint can withstand steady state heat flux of 10 MW/m².The electron beam simulating experiments indicate that there were no hot spot and other degradation failures with 12 MW/m² during 1000 cycles thermal fatigue test on the flat carbon fibre reinforced carbon attaching structure and there were also no obvious degradation failure in monoblock attaching structure after 300 cycles thermal fatigue test with 15 MW/m².The above results show that this kind of attaching technique can meet the requirements of the EAST device with high heat flux of 5-8 MW/m².