A wide-band laser cladding powder feeding head comprises a vertically adjusting plate body, a fixing plate and a powder feeding structure, wherein the cross section of the vertically adjusting plate body is U-shaped; stripped sliding chutes are respectively formed in two side edges of the vertically adjusting plate body in the longitudinal direction; the fixing plate is L-shaped; a short side edge is fixed on the stripped sliding chutes in the two sides of the vertically adjusting plate body in the transverse direction; the powder feeding structure comprises a powder feeding connector, a powder feeding pipe and a powder feeding nozzle; the powder feeding connector is a cylinder; a threaded hole is formed in one side wall of the cylinder in the transverse direction; the powder feeding connector is transversely placed on the stripped sliding chutes in the two sides of the vertically adjusting plate body; one end of the powder feeding pipe is screwed on the threaded hole in the powder feeding connector; the powder feeding nozzle is fixed at the other end of the powder feeding pipe. The wide-band rectangular powder feeding effect is obtained through the shaping of the conveyed metal powder, the wide-band powder feeding matched with rectangular laser beams is realized, the relatively wide-band laser cladding is realized, and the laser cladding efficiency is improved. The powder feeding nozzle is simple in structure, and is convenient to mount.