The invention discloses a method and system for electroplating efficiency self-learning control and relates to the technical field of steel. The method for electroplating efficiency self-learning control comprises the steps that width and the thickness of a raw material roll of current coiled steel and the thickness of a set plating layer are acquired; according to the thickness of the set platinglayer, the plating layer code corresponding to the thickness of the set plating layer of the raw material roll of the current coiled steel is acquired; it is judged whether the width and the thickness of the raw material roll of the current coiled steel and the plating layer code exist in an electroplating efficiency set value storage list or not; if yes, an original electroplating efficiency value, in the electroplating efficiency set value storage list, of current coiled steel is extracted, an average value is obtained from the original electroplating efficiency value and the actual electroplating efficiency value of the current coiled steel, and the electroplating efficiency average value is acquired; and according to the electroplating efficiency average value, next roll of coiled steel is controlled to be electroplated. By means of the method for electroplating efficiency self-learning control, accurate control over belt steel plating layer thickness by a production line can be achieved, and the technical problem in relevant technology that control over the plating layer actual thickness is inaccurate when an order plating layer changes is solved.