Abstract: Restricted by the surrounding terrain conditions and environment, the flood diversion sluice of Chaohu Zhaohe has an arrangement vertical to the axis of the river channel, and thus the river inflow conditions are not favorable. In view of the characteristics of the flood diversion sluice located vertically to the axis of the river channel, experimental analysis of the inlet flow patterns of the flood diversion sluice under the working conditions of open type and culvert type are carried out in a hydraulic model. The model test results show that the inlet flow patterns of the flood diversion sluice under the working conditions of the culvert type are much better than those of the open type release, which well keeps uniform flow incoming into the gate openings. Therefore, aiming at the scheme of the culvert-type flood release, analysis of the discharge capacity of the open release and controlled release of the flood diversion sluice is made, pointing out that the impacts given by the approach velocity upon discharge calculation should be taken into account during the sluice design calculation. In order to improve energy dissipation effects and the outlet flow patterns inflowing into the lower reach, the multiobjective energy dissipation tests with erosion control are made at the same time. The test results indicate that an impact-type energy dissipater having a baffle sill, located on the end of the deep-cut stilling basin, can make the outlet velocity distribution much more uniform and the outlet flow more smooth into the lower flow, and can significantly increase the effects of the energy dissipation and erosion control of the flood diversion sluice.