The goal of AHPGrey Relational Analysis model is to solve problems during selecting the best waterworks sludge treatment process.And grey Relational Analysis is to confirm the compactness between the ideal process and candidate process.Moreover, weighting system was determined by the threemark matrix and consistency analysis of judgment matrix for traditional AHP was improved by the optimum transfer matrix.Base on these theories, AHPGRA model was established.A case study was addressed with the selection of waterworks sludge treatment process in Chongqing.It is found that this model is legitimate and credible.