In order to improve the operational performance and water supply benefits of pump unit after transformation, based on pump running correlation function and flow governing characteristic by frequency conversion, the assessment and analysis of technical transformation program for the three-level pumping station in Shaizhudong Irrigation District has been done, and the water-pump control tactics which has good matched with actual project has been confirmed. The designing application shows that the power frequency signal generated by inverter intelligent operation can match irrigation water demand, and through frequency to realize speed change can dynamically and accurately adjustment water flow under no changing tube resistance characteristics. After reasonable technological transformation, the power conversion efficiency and automation control level is improved. The operating energy consumption has been reduced with fast response of flow adjustment and high reliability operation. The pump station can realize the aims of energy conservation and consumption reduction at the same time of technical upgrading.