The mixing effect in two horizontal opposed impinging stream mixer under turbulent flow condition was studied by using plane laser induced fluorescence (PLIF) technique, the influence of Reynolds number, the nozzle separation, the nozzle diameter and the inlet velocity ratio. The results showed that when the distance between two nozzles L increased from d’ to 3d’ (d’ was the average inner diameter between two nozzles), the mixing time decreased, but when L increased from 3d’ to 5d’, the mixing time increased, when L was 3d’, the mixing time was the smallest. When the Reynolds numbers was equal to 17544 at both ends of the inlet, the mixing time gradually decreases as the diameter of the nozzle increased from 6 mm to 14 mm, but the trend gradually slowed down. When the ratio of the inlet velocity of the two nozzles increased from 0.71 to 1.67, the mixing time decreased and then increased, when the velocity ratio was 1, the mixing time was the smallest. With the Reynolds number increasing from 7519 to 40936, the mixing time decreased. The mixing effect was best when L was 3d’ under symmetrical impact, the increase of nozzle diameter and Reynolds number can enhance the mixing effect significantly.