[目的]酸奶的粒径分布对其口感、稳定性和消化吸收具有重要影响,而激光粒度仪的测定结果易受样品前处理条件的影响。[方法]本研究系统探讨不同稀释比例（1︰1~1︰20）、遮光度（0%~25%）对酸奶粒径测定的影响,旨在建立标准化检测方法。[结果]稀释比例为1︰10时,D50平均值最接近真实值（20.766 μm）,相对标准偏差（RSD）最小（1.52%）,且粒径分布最集中（D90/D10=2.28）。遮光度在5%~10%范围内时,测定精密度最佳（RSD=1.50%）。基于此,推荐采用玻璃棒搅拌混匀样品、1︰10稀释比例、5%~10%遮光度作为标准化操作流程。[结论]本研究为乳品企业的质量控制、学术研究提供可靠的方法依据。

[Objective]The particle size distribution of yogurt significantly affects its taste,stability,and digestibility,while the measurement results of laser particle size analyzers are susceptible to sample pretreatment conditions.[Method]This study systematically investigated the effects of different dilution ratios（1︰1~1︰20） and obscuration levels（0%~25%） on yogurt particle size measurement,aiming to establish a standardized detection method.[Result]The results showed that at a dilution ratio of 1︰10,the D50 average value was closest to the true value（20.766 μm）,with the smallest relative standard deviation（RSD=1.52%） and the most concentrated particle size distribution（D90/D10=2.28）.When the obscuration level was within 5%~10%,the measurement precision was optimal（RSD=1.50%）.Based on these findings,a standardized operation protocol is recommended,including sample homogenization by glass rod stirring,a 1︰10 dilution ratio,and an obscuration level of 5%~10%.[Conclusion]This study provided a reliable methodological reference for quality control in dairy enterprises and academic research.