Laser cutting injection nozzle having connection sleeve

The utility model provides a laser cutting injection nozzle that has connection sleeve, which comprises an injection nozzle, an insulation ring, an inner casing, an injection nozzle seat and an injection nozzle component that is composed of testing equipment connection ports. A connection sleeve is connected with the upper end of the injection nozzle, and the upper end of the connection sleeve is provided with a screw thread. The cavity of the injection nozzle is a taper structure that has a bigger taper degree in the upper section and a small taper degree in the lower section. The top of the injection nozzle is designed as a structure with a collimation mouth. The inner casing and the injection nozzle seat are fixed by an insulating forelock. The insulation ring is a ceramic separation ring. The cavity of the injection nozzle has a taper scope: the taper degree A in lower section is equal to 20-30 degrees, the taper degree B in upper section is equal to 45-55 degrees, and the taper degree D in the cavity of the inner casing is equal to 20-30 degrees. The joint between the connection sleeve and the inner casing is a transitional slant touch. The taper degree of the cavity of the inner casing is small than the taper degree of the cavity of the injection nozzle.