The invention discloses a machining method for a hot stamping part based on the self-resistance heating performance gradient. The machining method comprises the steps that the hot stamping part is divided into a collision energy absorption area and a high-intensity area; a plate blank is cut into the corresponding shape, placed between electrodes on the two sides of a large-power power source and fastened through ejection air cylinders; the plate blank in the collision energy absorption area is subjected to short circuit operation through short circuit blocks, a low-temperature area is formed, and the corresponding high-intensity area is a high-temperature area; the high-temperature area is fully austenitized through the large-power power source, the temperature of the low-temperature area is maintained stable under the action of the short circuit blocks, and a plate blank with the temperature gradient is formed; and the ejection air cylinders release pressure finally, so that the hot stamping part with the gradient performance is obtained after stamping and quenching in a die are conducted. The machining method for the hot stamping part based on the self-resistance heating performance gradient has the advantages of being high in heating efficiency, low in energy consumption, capable of reducing blank oxidation and the like; the die design difficulty is lowered, and industrialization is easy; and the comprehensive collision performance of the hot forming part is improved on the premise that the intensity is ensured.