Abstract: In order to analyze the influence of the vane angle on the performance in saddle zone of the axial flow pump, the operation characteristics with different vane angles were tested by the axial flow pump with specific speed of 822 RPM. The research shows that with the increase of vane angle, the head, flow and efficiency of the test pump increase at the optimal working conditions at the same time, and the increase ranges are 10.4%, 26.7% and 0.87% respectively when vane angle changes from -4° to +4°. Under different vane angles, the head curves all present obvious saddle area. With the increase of the vane angle, the coefficient of relative head decreases gradually. It shows that the performance of saddle area is improved with the decrease of the vane angle. The absolute position in the saddle zone of the test pump deviates to the upper right, but the relative position is still mainly located in the range of 0.5QBEP-0.6 QBEP (QBEP is the flow when efficiency reaches the maximum), and the head reaches a minimum at 0.55QBEP. The pressure pulsation at monitoring point of impeller inlet under different vane angels is obvious with the feature of 4 peaks and 4 troughs in a single cycle. Under the optimal operating conditions, the pressure fluctuation curve at monitoring point of pump outlet is a regular sine wave, and there are also 4 wave peaks and 4 wave valleys in each cycle, and the peak value of pressure fluctuating peak at monitoring point of pump outlet increase with the decrease of flow rate. With the change of vane angles, the peak value of the pressure fluctuating peak in the saddle area is obviously larger than the optimal operating condition at the monitoring points of impeller inlet and pump outlet. With the increase of the vane angle, the pressure fluctuation in the 0.6QBEP becomes intense, and the pressure fluctuation in the 0.55QBEP increases first and then decreases. When the vane angle increases, the flow rate at monitoring point of impeller inlet decreases and when the flow changes from 1.0QBEP to 0.6QBEP, the peak value of the pressure fluctuating peak changes gradually, and the pressure fluctuating peak value of each angle changes violently as the flow changes from 0.6QBEP to 0.55QBEP. With the decrease of the relative flow, the pressure pulsation under different vane angles increases gradually. When the relative flow reached the range of saddle area, the amplitude of low frequency pulsation increases gradually, and when the flow rate continues to decrease, the broadband frequency distribution moves to the low frequency band, and the amplitude of low frequency increases. The main frequency of pressure pulsation at the pump outlet in the saddle area is basically stable at 6 APF (axial passing frequency) and the secondary frequency is stable at 4 APF. It shows that the pressure pulsation of the pump outlet is mainly influenced by the guide vane, and is also influenced by the blade passing frequency. The main frequency of the pressure pulsation at impeller inlet is the blade passing frequency, as the main frequency at the pump outlet is the guide vane passing frequency, and it moves to high frequency with the decrease of flow gradually. With the increase of the vane angle, the amplitudes of main frequency of pressure fluctuation at the impeller inlet, guide vane and pump outlet all gradually increase. At the impeller inlet, the maximum amplitudes of pressure fluctuation at 0.6QBEP and 0.55QBEP were 1.78 and 1.65 times respectively, and at the outlet of the pump, the amplitude of pressure pulsation at the positive angles is increased relative to the negative angles. Finally, the results of numerical simulation show that there is a backflow phenomenon at the impeller inlet under the small flow condition, and the vortex near the hub leads to the increase of the pressure fluctuation amplitude in the small flow condition.