The structure of a gate station with a combined pumping station tends to be complicated，where instable flow regime is likely to exist in the forebay.This article takes a pump station for example and uses physical model tests to make a prediction for its flow regime of front pool.Under the condition of designed water level of pumping station，the model test is performed when 6 pumps are fully-open and the self-draining holes are closed，providing reference for the analysis of flow regime of front pool of station-integrated pumping station.The test results show that under the original design scheme，there is a counterclockwise swirling flow in the forebay，and the scope of the swirling flow is mainly around the diversion wall，which is easy to produce cavitation in the pump.Aimed at the shortcomings of the original design，it was improved and a better design was obtained，that is，the method of extending the diversion wall，opening three holes and adding a stilling pier in the front pool，which can effectively improve the pump Station water conditions.