In order to investigate the influence of division pier on the pressure fluctuation and internal flow of outlet conduitat different rotational speeds, some high-precision digital pressure sensors CY302 and red threads were installed in the straight outlet conduit, fluctuating pressure signals were obtained and recorded under different operating conditions. The results showed that read threads were inclined under the small flowrate condition, while red threads were horizontal approximately under the optimal and large flowrate conditions. With the increase of flowrate, read threads were more horizontal. Under the same conditions of rotational speed and flowrate, the average values of pulsating amplitude root mean square in the straight outlet conduits without division pier were larger than that in the straight outlet conduits with division pier. With the increase of flowrate, the root mean square of pulsating amplitude was decreased gradually at the same rotational speed for straight outlet conduits with and without division pier. At the same flowrate, with the increase of rotational speed, the root mean square of pulsating amplitude was increased gradually for straight outlet conduits with and without division pier. The main frequency of each measuring points was the integer multiple relationship with the rotational frequency under the optimal operating condition of different rotational speeds for the straight outlet conduit with division pier, while the main frequency of each measuring points was not that. Division pier can improve flow pattern of straight outlet conduit, decrease the pulsating amplitude, but the improvement effect was also depended on guide vane outlet velocity circulation and flowrate under different operating conditions.