The construction of water conservancy project will inevitably have some impact on the surrounding ecological environment, while construction of the water conservancy facilities is indispensable for the full play of wetland ecological function. It involving how to avoid damage to the local ecological environment in the process of large-scale water conservancy construction has become an important problem that construction of China's water conservancy project has to face.This paper analyses the construction of Qilihai south pumping station’s ecological and environmental impact on Qilihai wetland to give an example for the impact of water conservancy project.