In view of the complexity of fluid distribution and the randomness of flow changes in the production process of oil wells, flow imaging measurement encounters serious challenges. In particular, key technologies such as the establishment of sensitivity fields, the fusion of multi-mode data, and flow image reconstruction are all in need of breakthroughs. In this paper, according to the characteristics of the physical detection field, based on the theory of imaging measurement, we focus on the research into a new dual-mode sensitivity field, the fusion of real and imaginary parts of the measurement data from the array sensor and the holographic tomography method with high efficiency and feasibility. Further, we investigate the feasibility and accuracy of holographic tomography through simulated flow measurement experiments. The research results in this paper show that holographic measurement data vary significantly, which highlights the differences in the conductivity and permittivity properties of various phases of fluid. The holographic measurement sensitivity field is more suitable for electromagnetic holographic measurement of multiphase flow in oil wells than previous sensitivity fields and the dual-mode fusion-based holographic tomography method is useful for improving the accuracy of holographic tomography. By carrying out a series of specific procedures in simulated flow measurement experiments, we can finally obtain the typical flow patterns of clearer gas-water interfaces and calculates flow parameter of considerable precision, which shows that the electromagnetic holographic method is feasible and has good prospects for application.