Electrodehydration is an efficient method to solve the difficult crude oil production fluid dehydration problem. Droplet deformation, droplet coalescence, droplet sedimentation and droplet-interface coalescence commonly occur during crude oil electrodehydration. The electric field parameters and physical property parameters have a significant influence on the droplet coalescence efficiency. The droplet-interface electrocoalescence process was investigated using COMSOL Multiphysics software. According to the field conditions of oilfield, the droplet-interface dynamic evolution behaviors were studied by changing the electric field parameters (electric field strength and electric field waveform) and physical property parameters (surface tension, electric conductivity, continuous phase viscosity, droplet size droplet-interface distance). The results showed that the droplet-interface partial coalescence degree increased with increasing electric field strength, droplet size and droplet-interface distance and the droplet-interface complete coalescence occurred at CaE≤5.61, D<0.69D0. The droplet-interface partial coalescence degree decreased with increasing surface tension and continuous phase viscosity, and the droplet-interface complete coalescence occurred at γ*>4.0 and Oh≥0.076. Compared with the DC field, pulsed field with different waveforms can effectively promote droplet-interface coalescence. When σ*≤1.0, with increasing electrical conductivity, the droplet dipole moment increased, and the surface charge movement and transfer speed increased, the dimensionless secondary droplet volume (Vr) increased significantly; When σ*>1.0, the change of droplet dipole moment is small and stable, and Vr gradually decreased, thus the droplet-interface partial coalescence degree first increased and then decreased. The research results provide a theoretical basis and research basis for the design and development of efficient and compact electrodehydration equipment, which has important academic significance and broad application prospect for energy saving, carbon reduction and green low-carbon transformation of oilfield.