The new fishway with the combination of ecological landscape lake and ecological imitation fishway was constructed for Dateng Gorge Hydraulic Complex. It solves the problem that the flow velocity in the outlet connection section of nature-like fishways too large to meet the normal reproduction and migration of fish. A variety of pipe pile structures with different diameters of circular and square plum-blossom piles are set up in the outlet connection section, and MIKE 3 is used for numerical simulation. The table of four kinds of pipe pile layout, the distribution of middle and bottom velocity and the hydraulic characteristics of the cross section behind each group of pipe pile group are analyzed. The results show that the flow pattern of the connecting section is stable after the pipe pile structure is laid. The flow velocity of round pipe pile with diameter of 0.25m and square pipe pile with side length of 0.25m satisfies the upstream condition of target fish. The square pipe pile has a lower flow rate and is more suitable for fish ascending. The pipe pile structure in the outlet connection section can effectively improve the flow pattern and reduce the velocity. Upstream fish resting in the low velocity zone behind the pipe pile can add color to the ecological landscape of the upstream lake.