Glyoxal and methylglyoxal are two typical types of α-dicarbonyl compounds in the atmospheric environment. The concentration variation is an important characterization of the oxidation process and reaction activity of atmospheric VOCs, which is of great significance for studying the oxidation reaction of the atmosphere. However, the characteristics of extremely low concentrations, short lifetime, and strong activity of glyoxal and methylglyoxal bring out certain challenges to accurately detecting their concentrations, resulting in limited monitoring results of the field environment and a lack of research on the mechanism of atmospheric chemical reactions. Several methods have been developed for detecting α-dicarbonyl compounds, such as chemical derivatization and mass spectrometry, which can effectively achieve gas concentration monitoring, but the technology also has certain limitations. In recent years, with the advancement of optical technology, a series of spectral methods has developed, such as Differential Optical Absorption Spectroscopy, Cavity Enhanced Absorption Spectroscopy, Laser-Induced Phosphorescence, Fourier transform infrared, and other technologies, which have the characteristics of non-contact detection, low detection limit, high sensitivity, and high time resolution. This article summarizes the current status and development trends of spectral technology and provides a detailed explanation of the principle, key procedures, advantages, and disadvantages of the method. The article also lists the key features of the technology, such as device parameters, retrieval algorithm, detection limit, and relevant applications. At the same time, for the calibration requirements for the high activity α-dicarbonyl compounds, commonly used calibration methods, such as airflow dilution, temperature-controlled bubbler method, heating method, and atmospheric reaction method, were detailed and described and made a comparison. Finally, the field observation experiments of α-dicarbonyl compounds were summarized, including the experimental conditions, concentration results, and main conclusions, which indicated that spectral technology is a powerful tool for glyoxal and methylglyoxal detection. Some analysis of the correlation between concentration changes and primary pollution emissions, VOC oxidation, and secondary organic aerosol generation are carried out. The mixing ratio of formaldehyde, glyoxal, and methylglyoxal was mainly discussed, and the range of mixing ratio values under different environments was obtained. Some results indicate that RGF has lower values in BVOC environments, and a high mixing ratio may indicate the impact of artificial VOC sources.