The present invention relates to a method for controlling supplied energy of each ignition plug mounted in a ship engine. More specifically, the present invention is configured to increase durability by minimizing abrasion of an electrode of the ignition plug caused by excessive supply of energy. To achieve the purpose, the method for controlling supplied energy of an ignition plug comprises: a step of measuring a required voltage of the ignition plug to be mounted in a cylinder head of an engine; a step of inputting measured required voltage data to an ignition controller; a step of calculating supplied energy in accordance with the inputted required voltage to build a database of energy to be supplied for each ignition plug; and a step of supplying the supplied energy corresponding to each ignition plug to the corresponding ignition plug.
