The forecast and balance of axial force is the key and difficult aspect in the design of multistage pump.150QJ20 type deep-well centrifugal pump was chosen as an example; the whole flow field of two-stage deep-well centrifugal pump was simulated in Fluent by the standard k—εturbulence model, SIMPLEC algorithm and second-order upwind scheme. The pump efficiency, single-stage head and single-stage axial force at different operating points were obtained by numerical simulations. The external performance and axial force of the prototype pump were tested by the experiments. The difference between numerical results and the experimental result were compared and analyzed. The results indicated that the numerical methods could accurately forecast the pump performance and axial force.