Through the hydraulic model test of Taoyuan river Reservoir project, the rationality of spillway layout and the possibility of optimization are verified. The spillway adopts the method of energy dissipation by means of flow-dissipation for flood discharge. Affected by the selection of the dam site, the spillway is located on the bend of the river. In order to make the deflector tongue fall into the river channel, the plan of deflecting the right wall by 4° was initially considered. With the continuous increase, the water entry point of the water tongue gradually shifted to the right bank slope, forming a backflow with a large scope and intensity on the right side of the river channel, and at the same time, it continuously impacted the right bank slope, which had a certain impact on the safety and stability of the bank slope. In view of this phenomenon, five optimization schemes are proposed. The parameters of water flow, water tongue, and scour pit depth under the five optimization schemes are compared through experiments. The results show that the deflection of the right wall is 6.9°,and the deflection of the left wall is 8.6°.The differential scheme with high sill is the best, which has the effect of design optimization, and also provides reference and reference for other similar projects.