The invention discloses a fertilizing method for a high-efficiently utilizing nitrogen fertilizer on southern double-season rice. Through a technical scheme in the invention, fertilization of a nitrogen fertilizer on early rice and later rice can be carried out reasonably. The nitrogen fertilizer is utilized effectively and reasonably; waste of the nitrogen fertilizer is reduced; and a production cost is reduced. Meanwhile, environmental pollution caused by the waste of the nitrogen fertilizer is greatly reduced and additionally a yield of the double-season rice can be significantly increased. Therefore, the fertilizing method is significant in economic benefit, social benefit and ecological benefit.