Abstract: In the contradictions between urban expansion and scarcity of resources, and between flood disasters and economic development, it is a new method of flood disaster management to clarify the property rights of drainage rights, promote the marketization of drainage right trading, and guarantee the rationalization of drainage right pricing. This paper put forward for the first time the institutional guarantee of drainage right trading, four pricing principles of drainage right trading, and two levels of drainage right pricing theories. Based on the loss assessment method of flood disasters and the construction cost of flood control facilities, this paper calculated the cost of drainage right and established the meta-model of the flood losses. This paper further formed the cost model of drainage right, and proposed the trading strategy and pricing model under the overall optimal constraints, which theoretically proved the contribution of drainage right trading to the improvement of drainage efficiency of flood control. Finally, with the application of the spatial display simulation of socio-economic statistics, and combining water level data from hydrometric stations during the flood season in July 2016 with the socio-economic data of Nanjing and Jurong in the same year, this paper calculated that the average drainage right prices of Nanjing and Jurong at that time were respectively 18.30 and 5.97 yuan/m³,which confirmed the feasibility of drainage right trading in practice.