In order to assess the layout design of a sea water pump station ,the paper carried out its experiment on physical model. It is important to exercise care and judgement when selecting the model scale. The model scale must be selected rationally in order to achieve each of dynamic, geometric and kinematic similarity with the prototype, and to correctly reproduce any vortex action at the intake of pump suction. In order to improve the good operation of the system, the following measurements and observations must be carried out that are water level within the installation, flow rate drawn from each pump position, approach flow pattern and flow distribution, velocity conditions at the pump suction, vortex activity within the pump chamber. Pre-rotation and vortex at the pump suction appeared because of the worse flow distribution. Based on the cause analysis of vortex appearance, the different measures were used so as to eliminate the bad phenomenon and ensure the safety of pumping station.