Abstract:Abstract: The ecological environment protection of large-scale projects has been paid more and more attention to. However, engineering disturbance, lack of methodology and theory are the difficulties of making effective construction plans. In this research, we applied the distributed hydrological model (SWAT model) to explore the influence of Tianfu International airport construction to ecological hydrology of Juren River, which was partially occupied by the airport. The result showed that the R2 and NS were 0.81 and 0.71 in model calibration, 0.70 and 0.53 in model validation respectively, so the runoff simulation was reliable. Considering the airport construction and ecological compensation plans, two scenarios including "construction damage" and "downstream restoration" were set up. In "construction damage" scenario, the surface runoff increased by at least 10%, root infiltration increased by more than 20%, the actual evaporation value increased too, meanwhile the runoff and water production decreased, the results showed a significant construction damage effect. Surface runoff, water production and river runoff reduced significantly in "downstream restoration" scenario, so the ecological restoration is effective. This research provides a new idea and an objective basis for the construction plan of large-scale projects, which has certain instructive meaning to propose project ecological protection plans and ecological compensation strategies.