The hypersonic low temperature (HYLTE) nozzle is widely used in continuous wave (CW) DF/HF chemical laser. To realize the mixing performance of this kind of nozzle, the laser induced iodine fluorescence (LIIF) was used to visualize the mixing flowfield of the single HYLTE nozzle. The measured result is concordant with the theory and the mixing performance of the HYLTE nozzle is better than the trip and rampnozzles.