Abstract: Cloud is closely related to high impact weather. Satellite infrared radiances data provides a lot of information in cloudy area. However, the observation operator error caused by the initial cloud parameters errors and the nonlinear influence of cloud on radiation process is too large, and the error distribution is non Gaussian, which brings difficulties to the direct assimilation of satellite infrared data in cloudy conditions. Aiming at the key technical problems of direct assimilation of satellite infrared radiances data in cloudy conditions, this paper reviews and summarizes the research progress of assimilation methods, radiation transfer mode, control variables, background errors, cloud detection, observation errors setting and bias correction at home and abroad in recent 20 years. The results show that the trend of direct assimilation of satellite radiance data is to further supplement the cloud and rain information and improve the corresponding technology based on clear sky radiance assimilation technology, so as to realize the direct assimilation of satellite data under “all-weather” conditions. It is pointed out that the direct assimilation of satellite infrared radiances in cloudy conditions faces challenges in how to construct the control variables related to cloud parameters and their background errors, and how to eliminate the nonlinear influence of cloud on observation and observation operators. With the common development of observation technology, assimilation technology and model technology, satellite infrared radiances data will inevitably play a greater role in the field of numerical weather prediction. Key Words: cloudy condition；satellite infrared radiances； assimilation