水泵在小流量、低进口压力情况下容易受进口回流和空泡的相互作用而发生低频空泡脉动现象，严重影响供水系统的安全运行．文中利用开式水泵汽蚀实验台，对离心泵进口静压进行频谱分析和进口流动的可视化观察，发现最高效率点流量的４０％～６０％区域所发生的低频脉动最强．采用水泵系统外的高压水源和喷嘴向水泵进口喷射水流的方法对低频脉动有抑制作用，叙述了喷射流量、喷射方向、喷射水源（水泵系统外水源、水泵出口高压水）对脉动的影响． Under low flow rate and low inlet pressure, the pump is prone to pulsation of low frequency cavitation due to the interaction of inlet reflux and vacuole, which seriously affects the safe operation of the water supply system. In this paper, open pump cavitation experiment bench was used to analyze the spectrum of inlet static pressure of centrifugal pump and the visual observation of inlet flow. It was found that the lowest frequency ripple occurred in 40% ~ 60% of the maximum efficiency point flow. The method of injecting water flow to the pump inlet by high pressure water source and nozzle outside the pump system can restrain the low frequency pulsation. The influence of jet flow, injection direction, water source (water outside the pump system, high pressure water at the pump outlet) on the pulsation is described.