The Heihe River Basin in Gansu Province is faced with severe water resources shortage. It is of great significance to evaluate water resources shortage by using water resources carrying capacity index for sustainable utilization of water resources. An evaluation index system of water resources carrying capacity of Heihe River Basin in Gansu Province was constructed, and each index was weighted based on entropy weight method. Fuzzy comprehensive evaluation method and TOPSIS (technique for order preference by similarity to ideal solution) model were used to evaluate and verify the water resources carrying capacity of Heihe River Basin in Gansu Province from 2011 to 2022, and the grey model was used to predict the water resources carrying capacity from 2023 to 2030. The results show these as follows. The water resources carrying capacity during 2011-2022 show a fluctuating upward trend in Heihe River Basin in Gansu Province, and the state of water resources carrying capacity tends to be better. The average values of fuzzy comprehensive evaluation and TOPSIS model comprehensive evaluation are 0.406 and 0.438 respectively, and the whole model is in a critical bearing state. Water resource indicators such as water production modulus (8.677%), annual precipitation (7.496%), annual runoff(5.381%), population density (14.523%), water consumption for forestry, livestock, fishery and livestock (9.181%), water consumption per 10 000 yuan of GDP (6.037%), GDP (4.088%) and other social and economic indicators. Ecological and environmental indicators, such as water use efficiency (6.724%) and water-saving irrigation area (3.721%), have high weight and relative importance. The predicted results of water resources carrying capacity in Heihe River Basin in Gansu Province from 2023 to 2030 show an obvious upward trend, and the level of water resources carrying capacity is continuously enhanced. The results provide theoretical reference for the sustainable utilization of water resources and the coordination of the relationship between water resources, ecological protection and economic development in the Heihe River Basin and northwest China.