应用一种单粒子采样型激光测速（ＩＲＬＶ）系统测量了轴对称空气自由湍射流初始段的轴向平均速度、湍流度和速度概率密度函数分布。数据是用一台微处理机自动采集和处理的。实验表明，在一般情况下利用空气中的自然微粒也能实现速度测量。为了比较测量结果，同时用热线风速仪测量了平均速度。在核心流区两者的一致性较好；在射流边界层中，随着数据率的下降和湍流度的增加，速度偏置有增大的趋势。 A single particle sampling type laser velocity measuring (IRLV) system was used to measure the axial mean velocity, turbulence and velocity probability density function distribution of the initial free axial turbulent jet flow of axisymmetric air. Data is automatically collected and processed by a microprocessor. Experiments show that in general, the use of natural particles in the air can also measure the speed. In order to compare the measurement results, the mean velocity was measured simultaneously with a hot wire anemometer. In the core flow region, the consistency between the two is better. In the jet boundary layer, the velocity bias tends to increase as the data rate decreases and turbulence increases.