基于动态光散射法,采用同差探测实现了纳米流体分散体系的粒度测量。对体积分数为0.005%和0.0025%浓度的SiO_2/H_2O纳米流体颗粒粒径进行了测量,粒径的实验值的平均偏差分别为1.37%和1.39%,可以满足纳米颗粒粒径的高精度测量要求。两种浓度的SiO_2/H_2O纳米流体的平均粒径基本一致,偏差在实验的不确定度以内,且随时间无明显变化,证明了颗粒分散的稳定性,本方法可以用于纳米流体分散稳定性的评价。 Based on the dynamic light scattering method, the particle size measurement of nanofluid dispersion system was achieved by the same-difference detection. The particle size of SiO_2 / H_2O nanofluids with volume fraction of 0.005% and 0.0025% were measured. The average deviation of experimental values ​​of particle size were 1.37% and 1.39%, respectively, which could meet the requirement of high precision measurement of nanoparticle size . The average particle size of the two kinds of SiO 2 / H 2 O nanofluids is basically the same, the deviation is within the experimental uncertainty and no obvious change with time, which proves the stability of particle dispersion. The method can be used for the dispersion stability of nanofluids evaluation of.