Abstract: The inlet flow pattern of the lateral inlet forebay of the pumping station is poor,and it is easy to produce a large-scale reflux area,which leads to the deterioration of the flow pattern of the inlet forebay of the pumping station. In order to clarify the problem of the flow pattern disorder of the lateral inlet forebay of the pumping station,the Zhaishan Dagou pumping station project in Xuzhou City,Jiangsu Province is taken as the research object. Based on the Reynolds time-averaged N-S equation and the RNG k-ε model,the CFD technology is used to carry out the comparative analysis of the numerical simulation of the lateral inlet forebay of the pumping station under the operation of multiple units with and without rectification measures. The results show that there is a wide range of vortex in the intake pool of the three units without rectification measures. Through the analysis of multi-scheme rectification measures,compared with the original scheme,the flow velocity distribution of the inlet pool is uniform and the flow pattern is the best when the longitudinal bottom slope of the lateral inlet front pool is reduced and the arc guide wall is set up,and the average axial velocity distribution uniformity of the inlet bell tube inlet surface of each unit increases by about 10% compared with the original scheme. The research results of this paper provide a certain reference for the improvement of the flow pattern of the lateral inflow front pool of the pumping station.