To the east of the new Qingfeng Junction Locks on the Cao’e River，the original flap gate was dismantled and converted into a 10-hole sluice gate，with the Qingfeng Junction Power Station to the east of the sluice gate. The narrowing of the river channel downstream of the locks leads to adverse effects on the flow regime of the approach channel downstream of the locks due to the discharge of water from the spillway and the power station. Thus an overall physical model test was used to study the effect of different flow rates and spillway opening methods on the downstream approach channel of the locks. The test shows that when the river’s flow discharge is greater than 850 m3/s，no matter what kind of opening method for the sluice gate is used，the flow rate in the lock’s downstream approach channel cannot meet the specification requirements；when the river’s flow discharge is less than 850 m3/s，the way of using all the gates to open evenly is conducive to weakening the downstream backflow intensity of the sluice gate，and the channel’s flow rate meet the specification requirements.