The invention provides a method for removing organic nitrogen compounds from fuel by using a polyethyleneimine solvent. Extraction operation is performed on high-boiling range diesel oil, coal liquidoil and the like by using polyethyleneimine as an extractant, wherein the mass ratio of the extractant to the fuel is 0.2 to 3, and finally, the denitrification rate can reach 60% to 99%. According tothe invention, selected polyethyleneimine is not insoluble with the fuel, thereby avoiding oil pollution, and alkaline organic nitrogen and non-alkaline organic nitrogen in the fuel can be removed simultaneously.