Currently,climate change is regarded as one of the most important global environmental problems at home and abroad. Future climate change may further exacerbate the contradiction between supply and demand of water resources in China,and affect water resources carrying capacity. This paper,based on the summary of the water resources carrying capacity researches,systematically expounds the concept and connotation of water resources dynamic carrying capacity,and puts forward its calculation theoretical frames and the Prediction-Simulation-Optimization-Based Control Object Inversion method (namely PSO-COIM Model). By constructing the ARIMAX dynamic regression forecasting model of the meteorological factors such as temperature,precipitation and runoff,the paper,taking Tarim River Basin,which is the largest continental river in China,as a typical example,analyses and calculates its water resources dynamic carrying capacity in future different level years under the three kinds of climate situation:RCP8.5,RCP4.5 and RCP2.6. The results of the calculation can clearly reflect the carrying scale of water resources under different climate situations,also determine its carrying levels in the future predicted economic and social development situation,as well as provide the basis for the sustainable development of Tarim River Basin.