Aimed at the fuzzy and uncertainty problems in groundwater quality assessment, five-element connection number model was developed on the basis of entropy method and the SPA. According to the relationship between water samples measured values of each index and the level of the threshold, connection degree formula was structured. Combined with the entropy analysis the coefficient of weight was calculated, and groundwater quality was evaluated. The application of the model to access the groundwater quality of 4wells illustrates the feasibility and effectiveness of the method.