Abstract: If oilfield produced liquid is the W/O emulsion which has high moisture content, and there are Na⁺、Ca²⁺、Mg²⁺ and Cl^- plasma contained in water phase, the type and content of the ions will have a significant impact on emulsion droplet formation and rheological properties of the emulsion. Phase transition process of W/O emulsion can be promoted by adding inorganic salts appropriately. Adding only one different salt and their quantities is even, CaCl₂ has the most significant effect on emulsion droplet shape and particle size distribution, and this is followed by NaCl, MgCl₂ last; under the condition of adding two salts by an equal percentage, the successive order of factors affecting emulsion droplet shape and particle size distribution are CaCl₂-MgCl₂, NaCl-CaCl₂ NaCl-MgCl₂. For the same kind of inorganic salts, emulsion droplet dispersity becomes inferior and average particle size of emulsion becomes larger along with adding amount of salt. The regularity is not obvious between the adding amount and type of inorganic salt and rheological properties of emulsion because of the emulsion stability; if multiple salts are added, rheological properties of emulsion will be a joint action of these multiple salts, still submit to the characteristics of power-law fluids.