共振型光声光谱系统容易受到外界环境的影响，其中相对湿度对光声信号的影响会直接降低光声光谱技术在进行痕量气体检测或气溶胶光吸收系数测量时的准确性。利用自制的U形光声池，搭建了一套相对湿度可精确调节的光声光谱测量系统，通过测量不同相对湿度下光声系统的性能参数，分析了相对湿度对光声信号的影响，获得了不同相对湿度下光声信号的修正参数。利用该参数，测量了7172.699 cm-1波长处水分子的吸收，并定量分析了相对湿度的影响。该研究结果为光声光谱技术在不同相对湿度环境条件下的应用提供了重要参考。

The resonant photoacoustic spectroscopy system tends to be affected by the external environment, while the relative humidity has negative influence on the photoacoustic signal, which could reduce the accuracy of the photoacoustic spectroscopy technique for trace gas detection or aerosol light absorption coefficient measurement directly. A set of photoacoustic spectroscopy measurement system is built based on a homemade U-shaped photoacoustic cell, and its relative humidity can be precisely adjusted. Performance of the photoacoustic system is measured at different relative humidity, and the impact of relative humidity on photoacoustic signal is analyzed. The corrected parameters of the photoacoustic signal are also obtained based on the experimental results, with which the absorption of water molecules at 7172.699 cm-1 wavelength is measured and the effects of relative humidity are quantitatively analyzed. The result provides reference for the application of photoacoustic spectroscopy technology in different relative humidity conditions.