为了有效地测量风洞中的气体流速，以激光多普勒频移原理为基础，结合波长调制可调谐二极管激光吸收光谱(TDLAS)技术，利用HITRAN 数据库，选取氧气(O2)分子在13144.5 cm-1附近的吸收谱线作为研究对象。在软件中建立了气体流速测量模型，模拟分析了流速测量结果；在实验室中利用超声风洞装置，建立了一套基于波长调制-TDLAS技术的流速测量系统，通过实验，提取出O2的二次谐波信号，根据O2分子吸收谱线的二次谐波信号的频移量反演风洞中的气流速度。实验结果表明，在实验室环境下，系统测量流速达到707.6 m/s，符合超声风洞的设计，测量误差范围为5.47%。实验结果为基于波长调制-TDLAS方法测量流速的小型化系统研制以及飞行实验进行了前期准备。

In order to effectively measure gas flow rate in wind tunnel, based on the principle of laser Doppler frequency shift, combined with wavelength modulation tunable diode laser absorption spectroscopy (TDLAS) technology, using HITRAN database, oxygen (O2) molecular absorption spectral line near 13144.5 cm-1 is selected as the research object. A gas flow measurement model is built in the software, the flow velocity measurement results are simulated and analyzed. Supersonic wind tunnel devices are used in the laboratory to set up a set of wavelength modulation flow measurement system based on TDLAS technology. Through the experiment, second harmonic signal of O2 is extracted. According to the second harmonic of O2 molecular absorption spectral line frequency shift, the flow velocity in the wind tunnel is reversed. The experimental results show that, in the laboratory environment, velocity measured by the system reaches 707.6 m/s. The experimental results are consistent with the supersonic wind tunnel design, and the measurement error is 5.47% . The results prepare for the research of system miniaturization, which measures flow rate based on wavelength modulation - TDLAS, and flight experiments.