Tungsten(W) is a most promising plasma facing material (PFM) for the future fusion device due to the considerable properties of high melting point.low tritium retention and low erosion rate under plasma exposure.And it has been selected as the armor material for ITER divertor (baffle and dome surface) in initial phase and fuU coated first wall during D-T operation phase.However,many physical and en8ineering issues must be solved before the application of W as PFM.One critical issue is related to its thermal mismatch (i.e.the large discrepancy of coefficient of thermal expansion and elastic modulus) with copper based heat sink materials.To solve this problem,the concept of W/Cu functionally graded material (FGM) was proposed to joint W on Cu as plasma facing component (PFC).To evaluate the performance of W/Cu FGM under the in-situ heat flux of tokamak,a W/Cu FGM block with discontinuous distribution (-6 layers) were exposed in the edge plasma of HT-7 tokamak for ~210 cycles (shot number #110377 ~ #110587).The W/Cu FGM shows good performance of interface to withstand the thermal fatigue by qusai-stationary heat load in general.but the W surface was destroyed by the typical high transient flux with abnormal events occurrence.The damages were initially created by typical transient heat flux at surface.then extended deeply into the interface by quasi-stationary heat load deposition and would cause the failure of interface.Enhancing the plasma confinement quality surely helps to avoid such destruction.In point of W/Cu FGM.it is necessary to enhance the weakening grain boundary for the pure W layer by adding dispersive particles,such as TiC,La2O3,and so on.