Global warming is one of the major challenges facing the world, and the emission of greenhouse gases is the main cause of global warming, and the monitoring of greenhouse gases has become the focus of attention of various countries. The infrared spectroscopy measurement system is a measurement system that observes greenhouse gases by analyzing the infrared light in a specific spectrum in the atmosphere, which can realize high-precision quantitative detection of medium to long wave infrared CO2, CH4 and other greenhouse gas characteristic absorption spectral data, with the characteristics of high spectral resolution, wide spectral coverage and high signal-to-noise ratio. The infrared interferometer component is the core component of the infrared spectroscopy measurement system, because of the particularity of the band, it has a unique position in the optical application in the military, aerospace, energy and other fields, and the accuracy of the interferometer optical system and the stability of the swing speed of the angle mirror directly affect the spectral resolution, signal-to-noise ratio and other main performance of the monitor. Therefore, this paper focuses on the key technologies in the development of the medium to long wave infrared interferometer, and designs an integrated double-swing arm Fourier transform interferometer system, in which all components of the interferometer are installed on the main bearing plate of the interferometer, and the optical path difference of the two signals changes with the swing of the swing arm, so as to obtain the corresponding interference field at the output end of the interferometer, realize the dynamic interference modulation of the input beam, and realize the integrated design, thereby improving the overall space utilization rate and enhancing the observation stability. The working spectrum of the interferometer is 2 μm–15 μm, and the beam splitter and compensator are made of ZnSe material, with a diameter of 60 mm; The flexible pivot is used as the connecting element between the swing arm and the main bearing plate, and the percentage of Vc radial load relative to radial allowable load is 17.1%, and the percentage of Vt radial load relative to radial allowable load is 11.0%, which can meet the service life of 5 years. The voice coil motor is used as the driving element of the interferometer swing arm, and its working current torque coefficient is 0.16 Nm/A, which can meet the driving requirements. The total weight of the interferometer is 3775.4 g, and the overall strength meets the needs of ground use.