The invention discloses a method for reinforcing a fatigue crack in the end part of a vertical stiffening rib of a railway steel bridge I-shaped beam. The method comprises the step 1, a real bridge of a railway steel bridge is inspected, whether a fatigue crack occurs to the end part of a vertical stiffening rib of an I-shaped beam web of the railway steel bridge is determined, if yes, the step 2 is performed; step 2, a hole is drilled in the tip of the crack in the end part of the vertical stiffening rib with a magnetic drill as a crack-stopping hole, the diameter of the crack-stopping hole is 10 mm and same as the thickness of the I-shaped beam web, and at the same time, the tip of the crack in the end part of the vertical stiffening rib falls into the crack-stopping hole; step 3, two ends of the stiffening rib are connected with the I-shaped beam web by angle steel so as to enhance local rigidity and reduce outside surface deformation. The method has the advantages that the hole is drilled in the tip of the crack, and the angle steel is added on the I-shaped beam web, so that the crack can be effectively prevented from expanding; it is verified by the fatigue test that the local rigidity is effectively enhanced and the outside surface deformation is reduced with the method of adding the angle steel on the I-shaped beam web.