There is a complex geological condition in the left bank of Jinping First Stage Hydropower Station. The wedge's stabilizing is one of the most important problems in the project which is composed of several weak layers. Support methods such as pro-stressed anchors system and shear key were adopted to ensure wedge safety. In order to research the two support methods and construction processes' influence in slope stability, the slope continue excavating with the two support methods in deferent construction processes have been used for numerical simulation. After comparison of plastic zone and variation of displacement, it is find that pro-stressed anchors system have an effect on limiting the development of plastic zone, refilling shear keys have en effect on control the displacement of the fault f42-9 which is the bottom slip surface of the wedge. It is very important for the left bank slope stability that completed the two support methods in time. It is feasibly that to decide slope stabilizing by curves of relative displacement between two sides of typical wake layer.