To reveal the biophysical response mechanism of the energy interaction between the land surface and the atmosphere in terrestrial ecosystems under the background of the ecological restoration project, the paper analyzed the radiation budget characteristics of planted shrub ecosystem based on the radiation observation data in the Yanchi desert steppe area of Ningxia from 2019 to 2021. The response mechanism of albedo to biophysical factors was studied using random forest model and ensemble empirical mode decomposition method. The results show that: (1) The diurnal variation trends of the planted shrub ecosystem are generally similar across seasons; however, there are significant seasonal differences in the change amplitude, peak time, and daily average value. (2) Downwelling shortwave radiation and longwave radiation both show obvious seasonal single-peak change, and net radiation and net shortwave radiation also follow similar seasonal patterns. Downwelling shortwave radiation drives seasonal variation in net radiation. The albedo trend during the growing season exhibits a concave valley shape overall. (3) Soil water content, vapor pressure deficit and leaf area index are the primary biophysical factors that affect albedo. Albedo has a nonlinear response relationship to biophysical factors. (4) Precipitation events, coupled with soil moisture, drive short-term fluctuations in albedo, while intra-annual seasonal growth of planted shrub vegetation determines long-term albedo trends. This study enhances the understanding of radiation processes in planted shrub ecosystem of desert steppe area, reveals the key factors driving albedo changes, and provides scientific basis for desert ecosystem management.