With regard to the current credit evaluation index system of water conservancy construction market subject, the construction unit is taken as an example. The existing credit evaluation results are compared and analyzed. The questionnaire survey method is adopted to obtain the identity of the market subjects to the existing evaluation index. The reasons for the difference of the identification degree of the different indexes are analyzed. The corresponding improvement suggestions are put forward: to delete “portal and platform information”, “the proportion of fixed assets in total assets”, “construction annual output value” and other indices of low identification, and to improve the weights of “management quality”, “personnel quality” and “management system” and other indices with high identification.