Abstract: Residual radial and axial forces generated by pump in operations are the root of noise, vibration, bearing temperature rise and transmissionparts damage. Stress state of DZY pump bearing in the system operation is analyzed. In addition, cause and balanced approach of radialand axial forces on the pump impellers are discussed systematically. An oil transportation company inland was subject to a pump damageaccident in the operation and commission. Thrust bearing damage is mainly caused by the axial force, especially that caused by motormagnetic center displacement when the pump starts. Bush damage is primarily caused by radial force. It is also proposed that the root ofpump damage is insufficient accuracy in manufacturing and installation. Through rotor repair, implementation of balance experiments as wellas inspection and adjustment of the motor's magnetic center, the problem in thrust bearing and bush is solved. Finally, some suggestions areproposed to reduce damage to rotor bearings in use, which can provide a reference to the safe operation of the pump.