The water conservancy project of Feilaixia located in the middle reaches of Beijiang river.The new second & third-lane locks are arranged parallely with the effective dimensions of 220 m×34 m×4.5 m (length×width×threshold depth),and the maximum design head is 14.44 m,using lock-bottom long-culvert & side-hole water conveyance system and layout pattern of energy dissipation with double open ditches.Carrying out an experimental study on the layout pattern of the conveyance system and hydraulic characteristics through the model test in 1:30 scale,we draw the conclusion that chamber delivery time,water hydraulic parameters,chamber berthing conditions,import and export of layout pattern can meet the specification requirements.It has been optimized to better conditions for the berthing chamber.