The invention relates to the image processing field and more particularly, to an automatic detection method and apparatus for oil leakage of current transformer wherein the method comprises the following steps: obtaining a foreground moving object from an obtained image sequence; determining a candidate region in the foreground moving object; performs double Gaussian fitting on the gray histogram of the candidate region; and according to the fitting result, automatically detecting whether the candidate region has oil leakage or not. The apparatus includes an image obtaining unit, a foreground object detection unit, a candidate region determining unit, and an oil leakage determining unit. The automatic detection method and apparatus for oil leakage of current transformer provided by the invention can detect the current transformer 24 hours a day without manual inspection, which saves human and financial resources and effectively excludes the erroneous inspections brought about by the influence of the external factors such as the change of the light condition, the shadow and the rain.