In order to study the unsteady pressure and velocity of the inlet region in the outlet conduit for the S-shaped shaft tubular pumping system, the whole flow passage of the pumping system was simulated based on the CFD technology. Comparison of numerical simulation results and experimental values under different operation conditions verifies the accuracy of the numerical model. The results show that, the maximum relative deviation of head coefficient is 3. 15%, and the maximum deviation of efficiency is 3. 07% in the range of simulated operating conditions compared with the experimental data. The distribution of axial velocity is affected by the number of the guide vane blades in the circumferential direction, and the wave trough number of the axial velocity filed in the circumferential direction is the same as the guide vane blade number. With the decrease of flow rate coefficient, the wave peak characteristic of the axial velocity filed is more obvious, and the wake characteristics increases gradually as well. When water flows through the outlet conduit, the pressure will increase and the velocity will decrease gradually. The rotation speed of impeller has little effect on the main frequency of inlet region in the outlet conduit. Both the inlet flowing pattern and flow improvement of guide vane have effects on the pressure fluctuation. The main and secondary frequency of every monitoring points are low frequency pulsation in different operating conditions.