In order to analyze the energy conversion characteristics of the impeller blades in multiphase pump quantitatively, the impeller performance in design working condition was studied under water and gasliquid two-phase flow, respectively. The results show that the capacity of impeller energy conversion gradually increases when the blade wrap angle changed from 0 to 60 degrees; when the wrap angle is larger than 60 degrees, the capability began to degenerate gradually, and the energy transfer performance of the pressure surface began to degrade. The enhancement of the energy transfer performance of the impeller pressure surface had a positive impact on the impeller energy conversion performance, but the enhancement of the energy transfer performance of the suction surface had an adverse effect on the impeller energy conversion performance. Under the gas-liquid two-phase case, the impeller power capability degraded, the energy conversion performance of impeller was worse than that of water alone. The research results had essential theoretical significance for the design of hydraulic optimization of the multiphase pump. (C) 2020 Elsevier Ltd. All rights reserved.