Provided is an electric desalting and dehydration apparatus, including an oil inlet distributor of an upper electric field, wherein the oil inlet distributor includes an oil inlet distributing pipe and an oil inlet branch pipe. The oil inlet distributing pipe is arranged in a water tray of an electric desalter, and below a ground electrode of the electric desalter. The oil inlet branch pipe is connected to the oil inlet distributing pipe to supply crude oil into the oil inlet distributing pipe. The oil inlet distributing pipe is provided with oil outlets on both sides thereof in a horizontal direction. The distributor can uniformly distribute crude oil in a water tray, thus all of the crude oil is kept in an electric field for an equal time.