Abstract: FeCo prealloyed powder for transition layer of laser welding diamond tools was fabricated by co-precipitation.The phase composition of the prealloyed powder was analysed by XRD and the morphology was observed by SEM.The relative density,hardness,bending strength and welding performance of the sintered samples fabricated by hot-press sintering with FeCo prealloyed powder were studied.The results show that the phase composition of prepared powder is FeCo(α′) phase;relative density of sintering samples increases with the sintering temperature increased,but hardness decreases.The variation of bending strength is litter by the sintering temperature increased;the welding performance of samples fabricated by higher temperature is better than that of lower temperature,the welding strength is reach 51.6 N·m at 850℃.