Emulsification viscosity reduction flooding in common heavy oil reservoirs is a comprehensive process of surfactant flooding and emulsion flooding，which includes both the interfacial tension reduction effect of surfactants and the control and flooding effect of emulsions. Therefore，the formation mechanism and migration characteristics of emulsions in porous media were first visualized by microphysical simulation. Then，the parallel experiments of natural outcrop long cores were used to conduct water flooding + emulsification viscosity reduction flooding and direct emulsification viscosity reduction flooding experiments. The effort was to further verify the flow characteristics of emulsification viscosity reduction flooding and comparatively analyze the oil displacement effects of emulsified viscosity reducer flooding. The experimental results show that emulsions are formed in situ under the action of shearing and interfacial tension reduction. These emulsions lead to frequent detour flow diversion of displacement media through clamping，bridging，and adsorption，which play the role of expanding swept volume and enhancing oil displacement. In the migration process，the emulsions interact with the porous media to demonstrate the flow characteristics of“slow and fast in respective three aspects.”The resulting percolation causes the distribution of emulsions to change regularly along the flow path and with the increase in the displacement ratio. The results of parallel core displacement experiments under different injection modes were compared. The result indicates that the starting pressure of direct emulsification viscosity reduction flooding（0.57 MPa）is lower than that of water flooding（1.52 MPa），and the injection pressure of emulsification viscosity reduction flooding after water flooding increases from 0.37 MPa to 1.17 MPa. The displacement pressure rises to an equilibrium in a fluctuating manner during the injection of the emulsified viscosity reducer solution. At the same injection ratio，the displacement efficiency of direct emulsification viscosity reduction flooding is increased by 16.69% than that of water flooding + emulsification viscosity reduction flooding. This further verifies that emulsification viscosity reduction flooding can effectively expand the swept volume and raise oil displacement efficiency.