In order to quantitatively evaluate the comprehensive benefits of low impact development(LID), taking ecological, economic and social factors into consideration to select sixteen LID measures evaluation indicators, including runoff cut rate, pollutant cut rate, cost investment, operational benefits, rainwater utilization, and ecological value, using analytic hierarchy process and entropy weight method to determine the index weight. The LID measure comprehensive benefits evaluation system is established based on the cloud model. The evaluation system are applied to a certain area of Nanjing to quantitatively evaluate the preliminary design schemes of 4 LID measures. The results show that the most effective scheme has the best pollution interception and emission reduction benefits and good social benefits. And it has the highest degree of subordination to the “better”, being the best scheme.