Long-path gas absorption cell is applied to a variety of spectral analysis and detection. Herriot Gas Cell with excellent chemical stability is mainly adopted, which is mainly composed of air chamber cavity, concave mirror, optical package structure assisted by high stability, standard optical fiber joint, power gas exploration inlet and outlet, shockproof base, etc. The unique suspension circuit design has excellent vibration and temperature stability, and can work in various complex environments, which is very suitable for gas line real-time detection. With ultra-low system noise, it can be applied to trace gas analysis. COx gas absorption cell is applied to spectral analysis and detection of CO and CO₂ gas.