Qianwei ship lock is an important joint project of Minjiang high-grade waterway，and its effective scale is 220 m× 34 m × 4.5 m（length×width×water depth on sill），design head is 19 m. Combining with the general layout of the project and in accordance with the requirements of the specification，we determine the decentralized water conveyance system form of lock wall long corridor and branch corridor at the bottom of the lock in Qianwei ship lock，and verify by the hydraulic calculation and model test. The results show that the layout of the water conveyance system and the opening mode of the valves are reasonable. The berthing conditions of the lock chamber and the flow conditions of the upstream and downstream water inlets and outlets are good，which can meet the requirements of the flow conditions and the safe operation of the water conveyance system，and achieve the expected goal.