The coaxial power-feeding nozzle, belonging to the field of laser processing equipment technology, is formed from laser channel, U-shaped fastener, outer ring, cone ring, cone cover, internal cooling water channel, external cuoling water channel and powder feeding channel, in which the laser channel is formed from light guide tube, cooling cover, reflector and internal cone body, and its internal cooling water channel is formed from water intake pipe, water intake channel, water discharge pipe, water discharge channel, internal ring water channel and its partion, board, its powder-feeding channel is composed of power-feeding pipe, ring mixing cavity and conical ring groove, it has 2-8 powder-feeding pipes which are distributed along the radial direction, and its external cooling water channel is formed from water-intake pipe, water outlet pipe, external ring water channel and its partion board.