<p>The Turpan–Hami basin, located in eastern Xinjiang, is one of the driest regions in China and the world. Despite its arid conditions, it serves as a key agricultural production area in Xinjiang, where the imbalance between water supply and demand poses a significant challenge. However, quantitative assessments of agricultural water resource carrying capacity in this region have been constrained by data limitations. In this study, we conducted a quantitative evaluation using field survey data and statistical data. By integrating Principal Component Analysis (PCA) and correlation analysis, we selected 11 independent evaluation indicators. A hybrid weighting strategy—combining the Analytic Hierarchy Process (AHP) and Entropy Weight Method (EWM)—was then employed to derive comprehensive weights. Finally, we synergistically applied Fuzzy Comprehensive Evaluation (FCE) and TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) to assess the agricultural water resources carrying capacity across counties. This dual-pronged approach, which integrates absolute grading (FCE) and relative ranking (TOPSIS), significantly strengthens the multidimensional validity and interpretability of the findings through complementary analytical perspectives. The results indicate that most counties are in an overloaded or saturated state regarding agricultural water resources, except for Barkol County, which is in a critical state. To balance water security and agricultural demands, the study suggests prioritizing irrigation modernization in overloaded areas (Gaochang District and Toksun County), promoting high water efficiency crops, and developing smart irrigation systems. This research provides a framework for evaluating the agricultural water resources carrying capacity and supports the formulation of sustainable agricultural water use strategies.</p>