Based on the interval crop water production functions under uncertainty,spring wheat, corn,cotton and honey dew melon were selected as study crops. Then the optimal allocation of water resources model in the Minqin irrigation region under uncertainty was established. Besides,to reflect the impact of climate change on irrigation water allocation,the uncertainty of meteorological factors (ET0 and RH) were also introduced in the model. The results show that the economic benefits per unit water of corn is low in the Minqin irrigation region and its optimal irrigation quota is larger than the current irrigation quota. Cotton has the biggest economic benefits per unit water in the Minqin irrigation region,followed by honey dew melon. In the case of limited available water and the premise of ensuring food security,the irrigation water for cotton and honey dew melon should be firstly ensured to reduce the economic loss. The model including meteorological factors has a wider range of interval solutions, which reflects the impact of meteorological factors on water allocation. This study verifies the feasibility of the uncertainty method in practical application and provides a more reliable scientific basis for the rational allocation of water resources in irrigation areas.