针对激光吸收光谱技术波长调制方法测量技术，提出了一种非分光多谱线二次谐波测量方法。通过调整谱线间相对位置，在无需光栅等分光装置条件下可实现对多谱线调制信号的解调制，进而在线测量气体温度。基于7185.60 cm^-1/7444.35 cm^-1 H₂O吸收谱线讨论了调制系数和谱线间相对位置对于测量的影响，结合调制信号频谱图分析了不同调制频率工况下的二次谐波提取方法。利用数值仿真方法建立了脉冲爆轰过程复杂流场变化模型，采用提出方法对脉冲爆轰过程燃气温度进行了测量，验证了该方法的正确性。研究结果对复杂环境条件下波长调制测量方法的应用具有重要意义。

Aiming at improving the measurement of wavelength modulation via laser absorption spectroscopy, a non-dispersive multi-wavelength second-harmonic measurement method is proposed. By adjusting the relative position between the spectral lines, the demodulation of the multispectral line modulation signal can be achieved without the need for a grating or other spectroscopic devices, and the gas temperature can then be measured online. Based on the 7185.60 cm^-1/7444.35 cm^-1 H₂O absorption spectrum, the influence of the modulation coefficient and the relative position between the spectral lines on the measurement are discussed. Further, the second-harmonic extraction method under different modulation frequency conditions is analyzed using the modulation signal spectrogram. A numerical simulation method is used to establish a complex flow-field change model in the pulse detonation process. The proposed method is used to measure gas temperature during the pulse detonation process, and its correctness is verified in this study. The research results are of great significance to the measurement of wavelength modulation under complex environmental conditions.