In order to test the performance of a new axial-flow waterjet pump, a scaled model pump bench test was carried out. The maximum opening state of the flow valve at multiple speeds was measured, and the power of the test pump under multiple flow conditions at the same speed was measured. The Reynolds time-average equation (RANS) was closed based on the SST turbulence model, and the structured grid was used to discretize the calculation domain. The external characteristic curve of the full-scale waterjet pump was calculated, and the data at the test pump scale was obtained by non-dimensional similar conversion. Based on the power loss analysis, the test value was compared with the calculated value. The result shows that they are in good agreement within the speed range of 1130~1760rpm, with a maximum error of 7.5%; the trend of the head characteristic curve reaches a good agreement under the condition of equal speed.