The invention provides a method for constructing a hydropower transferring transaction optimization model. The method includes the steps of calculating the storage capacity and power generating capacity of a hydropower station, establishing a power network model based on electric quantity to obtain line residual transmission limit, establishing a hydropower transferring transaction optimization model, converting the hydropower transferring transaction optimization model established into mixed integer planning for solving a solution. According to the method, water resource characteristics are taken into consideration, water resource characteristics and influence of seasonal factors on power generation of the hydropower station are comprehensively analyzed, and the influence of trend constraint on transferring in a typical operation period is also taken into consideration. Hydropower transferring transaction is optimized, and cross region transferring of hydropower for consumption is facilitated. Hydropower is fully used, and the low construction and operation cost of transferring channel is ensured.