How the gross primary productivity (GPP) and evapotranspiration (ET) of the planted shrub ecosystem in desert steppe areas responds to global climate change is not only a key scientific problem of global change ecology, but also relates to the sustainability of regional ecological restoration in arid and semi-arid areas. Considering different climate change scenarios and future trends, this study used meteorological and environmental data to drive the Biome-BGC model. The response of GPP and ET of the planted shrub ecosystem in the desert steppe area of Yanchi county to climate change was studied. The results show that: (1) air temperature rising significantly inhibits the GPP of the ecosystem. High-intensity warming (3 ℃) leads to a sharp decline in GPP, but the inhibitory effect of warming on ET is very weak. (2) Precipitation is a critical factor limiting the change of ET. Compared with the decrease of ET caused by drought stress under regional warming, the amount of precipitation controls the ET's magnitude of the ecosystem more directly. (3) The warm and humid climate and the increase of atmospheric CO₂ concentration in the future will have comprehensive effects on the ecosystem and ultimately promote the flux of carbon and water between land and atmosphere. The research can provide a scientific basis for human to adapt to global changes in arid and semi-arid areas and for local governments to implement ecological protection and restoration policies.