Abstract: Water hammer phenomena caused by maloperation at pump station usually happen during pipeline operation. It then leads to partial overpressure, liquid column separation and pump unit cavitations. In this paper, causes for water hammer are introduced. Especially, the compositions of automatic pressure regulation system, pressure overrun protection system and water hammer control system of Rizhao-Yizheng Crude Oil Pipeline are analyzed. The accident of incidental close of inlet valve in Yizheng Pump Station is simulated, to demonstrate the water hammer protection process of the pipeline. Results show that the water hammer protection system is feasible for Rizhao-Yizheng Crude Oil Pipeline, and it can effectively prevent serious water hammer and equipment damage.