FY-4A of China carries the Geostationary Interferometric Infrared Sounder (GIIRS) to realize infrared hyperspectral sounding on a geostationary orbit for the first time, which can continuously obtain information of atmospheric temperature and humidity profiles. Based on the conventional radiosonde data, the quality of FY-4A/GIIRS atmospheric temperature profile products in 2020 is evaluated from the aspects of detection capability and accuracy, providing reference for product applications and algorithm research. The results show that the detection ability of the atmospheric temperature profile retrieved by FY-4A/GIIRS is greatly affected by cloud activity in the height level and monthly statistics. Under clear sky conditions, the root mean square error of the whole atmospheric layer is about 2 K, while the lower atmospheric layer of 700-1 000 hPa is relatively larger (about 2.5 K). The bias of the whole atmospheric layer is mainly negative. The quality assessment of different months shows that summer and autumn are obviously better than winter and spring, which is conducive to observation in the season with the frequent disastrous weather. The temperature profile error of a single pixel is obviously large under cloudy conditions, and the multiple-pixel Cressman objective analysis can effectively improve the product availability. The product quality of temperature profiles in low altitude areas is significantly better than that in high altitude areas, which can greatly make up for the shortage of sounding data in the eastern, southern regions of China and the vast ocean surface.