Abstract: In order to better reflect the trend of water resources carrying capacity and its grade, this paper applies the principle of partial relation number and subtraction set to deal with the difference items in the five-element relation number twice from the general relation point of view. The method of double partial subtraction set pair potential is constructed, which reduces the remaining amount of difference term in five-element subtraction set pair potential and avoids the artificially set coefficient 0.5 in calculation. The application of this method in Huaibei Plain shows that: from 2015 to 2019, most of the water resources carrying capacities of the six cities in the Huaibei Plain were between levels 3 and 4, and only those of Suzhou, Bengbu and Huainan cities in 2018 were between level 2 and level 3, and the water resources carrying capacity of the six cities in the Huaibei Plain did not show partial homogeneity or homogeneity during 2015-2019, indicating that the overall water resources carrying capacity of the Huaibei Plain was weak. The method of double semi-partial subtraction set pair potential broadens the thinking of analyzing and evaluating the carrying capacity of water resources.