The benefit distribution mechanism of Water Saving Management Contract (WSMC) is imperfect, which affects its development process. Taking users and Water Service Companies (WSMC) as participants, this paper studies the benefit distribution of benefit guaranteed WSMC by using the hierarchical sharing model for the first time. Firstly, the degree of WSCO effort and knowledge input coefficient were selected as the influencing factors to establish the income model of both sides. Secondly, according to the change of influencing factors, it analyzed the enthusiasm of WSCO's efforts in the two cases of WSCO only obtaining management expenses and WSCO participating in excess profit distribution, and determined the profit proportion of both sides when making excess profits. Finally, an example was given to verify the effectiveness of the model. The results show that:(1) When WSCO participates in excess profit distribution, the degree of effort is higher and the total profit of the project is higher. (2) WSCO's work effort is positively correlated with the efficiency coefficient of knowledge input and the proportion of excess profit distribution. This paper provides a reference for the benefit distribution of WSMC under the benefit guarantee mode.