Abstract: A hydraulic model experiment about the project of energy dissipation with vertical stilling well indicated that the vertical stilling well is a reasonable and feasible measure when the flow changes from the conduit to the open flow under the high head and small discharge conditions.The vertical stilling well can bear much high head of the conveyer conduit, which is relative to the control valve installed on the import conduit.The analysis of theory indicated that the greater part of the pressure head of conveyer conduit is consumed on the valve.The valve is a key place on the project of energy dissipation well.The opening of valve should adapt to the pressure head.The velocity distributions in the expert conduit of energy dissipation well are large on the external curve, and are small on the internal curve.