A high-power laser welding head includes a guiding plate, an outer cover, an inner cover and a joint, the circumference of the guiding plate is arranged with screw thread which is connected with the sole cover of the outer cover, the center of the guiding plate is arranged with a light-pervious hole, an inner air ring and an outer air ring, the inner air ring is connected with the outer air ring with an air course and is butt-jointed with the lower end of the air course of the inner cover, the outer air ring is communicated with one end of the nozzle and the other end of the nozzle is communicated with the light-pervious hole. The present invention has the advantages of reasonable designing, compact structure, convenient installing, little maintenance amount, simple operation, small heating effect of the laser welding head as the forced cooling of air cooling and water cooling are simultaneously provided, adapting for the long-time work, insulating the welding zone from the outer air as the strong-unreactive shielding gas is sprayed during operation, smooth welding, small welding seam width, small heat affected zone, high welding efficiency, good effect, completing the fine welding which can not realized in the traditional technique, and wide adopting industries, the invention can be adopted in various industries of machine manufacturing, rubber plastic product, petroleum chemical industry, watercraft and submarine manufacturing, water conservancy and electric power, aviation and spaceflight, apparatus and instrument, communication and artwork, etc.