The impinging stream reactor currently under study, especially in processes of fluid mixing, is employed in a variety of applications that include pharmaceuticals, petroleum, and provisions. The distributions of three-dimensional velocity fluctuation in the dual nozzle opposed impinging stream mixer were measured experimentally using laser Doppler velocimetry (LDV). The results showed that stagnation points were in proximity of the line of z = 0 under experimental conditions, but the exact positions of these stagnation points shifted with different nozzle diameters, nozzle spacing, and inlet flow rates. The distributions of RMS velocity and turbulent kinetic energy were similar in the same operating condition, but turbulence intensity changed obviously on the z axis ranging from -10 mm to 30 mm, in which region turbulence was intense and the large turbulence intensity was advantageous to mixing. The RMS velocity was influenced obviously by changing distance between nozzles, the turbulence intensity was affected greatly by the nozzle diameters, and the region of high turbulent kinetic energy which was beneficial to mixing was enlarged by increasing inlet flow rates.