The acidizing cleanup emulsion phenomenon is serious, and it can not enter the power off process. In view of the above problems, indoor simulation experiments were carried out to explore the influence of temperature, pH value, moisture content, the oil phase of the returned liquid, the water phase of the returned liquid, the iron-containing compound and the mud content on electric dehydration of returned acidizing fluids. It was found that when the impurities in the oil were less, the water phase and water content of the returned acidizing fluids had little effect on the electric dehydration, the increasing of the temperature was beneficial to the effluent demulsification, and neutral pH value was the most suitable condition for the demulsification of the returned fluids. The ferric hydroxide colloid which was wrapped with crude oil, sludge and free water in oil, forming a very high conductivity intermediate layer between the oil phase and the water phase, was the main cause of electric dehydrator trip.