Abstract： In order to make non-clogging centrifugal pump meet the requirement of multiple operating conditions, optimization design of the 100QW110167.5 model pump impeller was done by using the unequal head hydraulic design method. Combining with the CFD numerical simulation technology, the internal flow field of the original scheme and new scheme were analyzed. It shows that the new impeller does work more fully, its flow lines distributed more uniformly and smoothly at different conditions, and the flow condition of the pump is improved. Besides, the optimal model prototype, based on the simulation, was tested. And the results show that the head of the model pump is 16.89 m and the efficiency reaches 83.11% at the rated point, which has exceeded energysaving level product requirement of the centrifugal water pump. At low flow conditions, no saddle area and no intense vibration phenomenon occure, meeting the design requirements. The efficiency curve, between 0.8q and 1.3q of its efficient region, has a wide efficient area. And the nonclogging performance is better than the original scheme. The predicted curve is basically consistent with the experimental one, and the maximum error is 7.56%, indicating that the numerical simulation is accurate.