本文描述了一个用于柴油机排气微粒测量的微型稀释风洞,它抽取并稀释部分排气,有尺寸小、造价低的特点,适用于发动机台架测试。排气在本风洞中经历两级稀释。设计了一个空气引射器作为第一级稀释装置。为便于测定微粒质量浓度,设计了低挡稀释比5～30;为了实现低浓度微粒采样,以便进行理论分析,设计了高挡稀释比100～300。 This paper describes a micro-dilution tunnel for diesel exhaust particle measurement, which extracts and dilutes a portion of the exhaust gas. It is small in size and low in cost and is suitable for engine bench testing. Exhaust gas undergoes two levels of dilution in this wind tunnel. An air ejector was designed as a first-stage dilution unit. In order to facilitate the determination of the concentration of microparticles, a low-block dilution ratio of 5-30 was designed. In order to achieve low-concentration microparticle sampling for theoretical analysis, a high-level dilution ratio of 100-300 was designed.