Abstract: Abstract: Similar transformation design method is one of the most frequently-used ways of centrifugal pump design. In order to verify the similarity of the scaling model, a typical submersible well pump was chosen as the model pump in this paper, and based on the scaling model conversion algorithm, the designed pump was obtained. And the designed pump model was directly scaled without any factor correction by the model pump with a scaling factor of 0.66. By the numerical simulation and the experiments, both the comparability between the model pump and the designed pump and the difference between their inner flow fields were analyzed. Ansys CFX software was adopted to simulate the flow fields of the designed pump and the model pump. The calculation domains were created based on two-stage pump models, which were meshed with the structured grids. The numerical simulations under multi-conditions were performed based on standard k-ω turbulence and standard wall function. Also, different number of grids were divided both for the model pump and the designed pump in this paper to determine the unrelated relationship between the number of meshes used in the calculation and the calculated results. The flow filed of liquid in the main flow passage were analyzed emphatically. The streamline on blade to blade surface and the turbulent kinetic energy distributions on middle section of the impeller were analyzed to get the flow state and the hydraulic loss inside the impellers for both the model pump and the designed pump. In the meantime, the static pressure distributions and the vortex core region inside the diffusers were investigated. By the comparative analysis between performance predicted, it was found that the designed pump and the model pump had basically consistent variation tendency of their head, efficiency and shaft power under 0.4-1.6 times rated flow conditions, Which meant the performance predicted meet the similar conversion rules. The designed pump and the model pump both have wide high efficiency area, and the highest efficiency points are both at 1.2 times rated flow rate condition. Compared to the model pump, the maximum shaft power point of designed pump shifted to the heavy flow rate conditions, and the ratio of maximum power and the rated power increased. But the designed pump still has better performance of non-overload. The streamline on blade to blade surface and the turbulent kinetic energy distributions on middle section of the impellers showed that the fluid flow field and the vortex area inside the impeller were consistent. Also, the static pressure distributions and the vortex core region inside the diffusers showed that the pressure distributions inside the diffusers were similar, but the vortex core area inside the designed pump was smaller than the model pump. So, the liquid inside the designed pump had a good internal flow state, which would make the designed pump having a hydraulic efficiency. By the comparison between results of numerical calculation and experiment of model pump, the head and power of numerical simulation predicted were slightly lower than the test results, the predicted efficiency was slightly higher than the test results, but the changing trend were almost the same. The results of this study could provide a basis and reference for the improvement of submersible well pump performance. As we can see, the designed pump narrowed by the model pump had good hydraulic performance, which meant that the model direct scaling method can meet the design requirements of deep well centrifugal pumps.