波导式光学吸收腔在气体和液体浓度测量等领域有广泛的应用前景。吸收腔的有效光程与系统的灵敏度有直接的关系。提出了波导式吸收腔有效光程率的数学模型。从理论上分析了波导的内壁镀膜折射率和厚度、波导内径和弯曲以及输入光场能量分布等因素对波导式吸收腔有效光程率的影响。对提高系统灵敏度和测试系统的误差补偿提供了重要参考。计算结果与已经发表的实验数据有很好的一致性。 Waveguide optical absorption chamber in the gas and liquid concentration measurement and other fields have a wide range of applications. The effective optical path of the absorption chamber has a direct relationship with the sensitivity of the system. A mathematical model of the effective optical path length of the waveguide absorption cavity is proposed. The influence of the refractive index and thickness of the inner wall of the waveguide, the inner diameter and bending of the waveguide, and the energy distribution of the input optical field on the effective optical path length of the waveguide absorption cavity is theoretically analyzed. It provides an important reference for improving system sensitivity and error compensation of test system. The calculated results are in good agreement with the published experimental data.