In order to investigate the uncertainty information conceived by the ternary connection number, the mutual transformation between the connection number components is fully considered in the reconstruction of the ternary connection number based on the ternary semipartial subtraction set pair potential, and the value intervals of the connection number components are obtained based on the triangular fuzzy number and partial connection number theory. In the meantime, the value of the connection number under a certain confidence level is determined by the random simulation method, according to which the water resources carrying capacity evaluation model based on semipartial subtraction set pair potential triangular fuzzy number stochastic simulation method (WRCC-SPSS) is constructed and then applied to the water resources carrying capacity evaluation in the Jianghuai hilly region, and is also compared and analyzed with the existing conventional methods. The results show that the water resources carrying capacity of the Jianghuai hilly region steadily enhanced from 2011 to 2018, and the carrying capacity of Hefei city performed the worst. The reconstruction of the connection number can reduce the uncertainty of the components, and the adoption of the triangular fuzzy number and stochastic simulation method can determine the confidence interval of the connection number, which are conducive to the reliability of the results. The results of the example application of WRCC-SPSS are generally consistent with the evaluation results of the existing research methods, because WRCC-SPSS is more focused on uncertainty, rich in physical content and applicable to the dynamic evaluation of the water resources carrying capacity.