Abstract: In order to research the pressure pulsation characteristics of vertical inline centrifugal pump under different conditions, the test was conducted by applying a dynamic frequency pressure sensor system under 4 different operating conditions, and the monitoring points of pressure were located on the inlet pipe and the volute. Both frequency and time-frequency characteristics were investigated in the experiment. The results show that the pressure pulsation at each monitoring point has a certain periodi-city. The amplitude of pulsation is the highest near the volute tongue. As the flow rate increases, the amplitude of each monitoring point first decreases and then increases. Except under 1.4Q_d condition, the dominant frequency of pressure pulsation at the inlet pipe is 2 times the shaft frequency, and the amplitude exhibits strong fluctuation characteristics. The dominant frequency of pressure pulsation at the volute tongue is of blade passing frequency, and its amplitude increases as the flow rate increases. It shows that wide frequency volatility at high frequency under 0.6Q_d and 1.0Q_d. The dominant frequency of the pressure pulsation at the volute diffuser is of blade passing frequency under 0.6Q_d and 1.0Q_d, and the main frequency under overload conditions is of shaft frequency. The amplitude of shaft frequency decreases as the flow rate increases.