Abstract Electric submersible pumps (ESPs) are widely used in both onshore and offshore oil fields. However, the impeller of an ESP has strong fluctuation and obvious disturbance structure under the condition of gas-liquid two-phase flow, which leads to significant performance degradation. Dynamic mode decomposition (DMD) method is a data-driven approach that can effectively identify the characteristic frequency of unsteady flow and capture the disturbance structure in the flow field. In this paper, DMD method is used to decompose and reconstruct the phase and velocity fields in the impeller of an ESP. The main modal structure and frequency information are obtained. The future flow field is predicted to verify the feasibility of DMD method within high-speed rotating flow fields. The results show that DMD method can effectively extract the main flow structure of the flow field in space and time, which can also be used to check the flow stability. Applying DMD method to the analysis of unsteady flow field is important for flow feature extraction, flow phenomenon analysis and flow mechanism interpretation.