To adapt to the future climate change and increased carbon emissions in the Longzhong region, this study proposes optimization strategies for the production management of rain-fed spring wheat. Based on field experimental data from Dingxi, Gansu, collected from 2014 to 2017, the Root Zone Water Quality Model 2 (RZWQM2) was calibrated and validated for this region. Using this model, climate projections under the RCP4.5 and RCP8.5 scenarios for the period 2025-2060 in Northwest China were analyzed. Different sowing dates and CO₂ concentration gradients (370, 400, 500 and 600 μmol·mol^-1) were applied to evaluate the impact of future climate change on spring wheat yield and LAI. The results show that, The model accurately simulated the leaf area index (LAI) and yield of spring wheat, with R₂ values reaching 0.913 and 0.992, respectively. Under the RCP4.5 scenario with moderate warming, when CO₂ concentration exceeds 500 μmol·mol^-1, significant yield increases were observed. The average yield increases for early sowing (March 7), conventional sowing (March 19), and late sowing (March 31) were 29.3%, 28.9%, and 24.7%, respectively. Under the RCP8.5 scenario, high temperatures, reduced radiation, and precipitation fluctuations weakened the CO₂ fertilization effect, resulting in a yield increase of only 20.9%-27.5%, with significant interannual variability. The sowing date effect was also prominent, with early sowing maintaining the highest and most stable yield and LAI in both climate scenarios, while late sowing, impacted by combined heat and drought stress, showed the highest yield fluctuation. In conclusion, under the future higher CO₂ concentrations, through coordinating reasonable early sowing and water and fertilizer management the risks of high temperature and water stress can be alleviated to increase the LAI and yield of spring wheat in Longzhong dryland.