Numerous impellers are placed in line on the same shaft in a multistage centrifugal pump, comprising an impeller, diffuser, and return channel. The design of a two‐stage multistage centrifugal pump according to the specifications given in the literature was created using Creo Parametric software and validated by carrying out a numerical simulation of the first‐stage centrifugal pump by varying the number of blades and impeller speed and concluding that the pump with 7 blades and 1900 rpm rotation gives the best efficiency and head by comparing the obtained results to experimental ones. ANSYS Fluent 2022R1 was used for simulation. The optimal solutions from the first stage were used to analyze the second stage. It was observed that losses in the diffuser of the 1st stage and 2nd stage are almost the same, but head losses in the return passage of the 1st stage and 2nd stage have differences of 19.99%, 28.5%, and 23.59% for 5, 6, and 7 blades, respectively. The findings show that the multistage simulation could more accurately mirror the actual flow than the two‐stage simulation, but it also had more demanding computer configuration requirements. A two‐stage simulation is a good option for estimating pump performance because it balances computation time and numerical precision better.