The invention relates to a quick-changing battery for a chassis. The quick-changing battery for the chassis comprises an upper box cover, a lower box body, an inner container fixed in the lower box body and a sealing structure arranged between the upper box cover and the lower box body, wherein the sealing structure comprises a sealing gasket and a connecting flanging arranged on the upper box cover; the upper surface of the side wall of the lower box body is provided with a smooth supporting surface; the side wall of the inner container is provided with a flange matched with the smooth supporting surface in an attached manner; and the sealing gasket is a flat gasket arranged between the flange and the lower surface of the connecting flanging. The flange matched with the smooth supporting surface in an attached manner is arranged on the side wall of the inner container, the integral smoothness and structural strength can be increased, and the deformation is reduced, so that the sealing gasket can be in tight fit with a corresponding sealing matching surface, and the sealing performance is greatly improved; and moreover, a vertical water blocking plate does not need to be arranged on the lower box body, so that the reduction of overall weight is facilitated, the processing difficulty is low, and the sealing effect is good.