The invention discloses a method for removing nitrogen through treating refuse leachate by using a two-stage feedwater mineralized refuse reactor. The method comprises the steps of arranging a two-stage mineralized refuse reactor combined system, carrying out synchronous nitration reaction on a certain ratio of leachate by using a first-stage mineralized refuse reactor to remove part of total nitrogen, and then, injecting the leachate into a second-stage mineralized refuse reactor; and meanwhile injecting the rest ratio of raw leachate serving as a supplementary carbon source to the second-stage mineralized refuse reactor, and further accelerating the denitrification of nitrate nitrogen of the leachate treated by the first-stage mineralized refuse reactor to increase the removal rate of the total nitrogen of the system. By using the two-stage mineralized refuse reactor combined system for treating the leachate in the method, a certain ratio of raw leachate is injected to the second-stage mineralized refuse reactor to supplement a denitrification carbon source on the basis that part of total nitrogen is removed by using the first-stage mineralized refuse reactor, so that the aim of removing nitrogen through denitrification is achieved to the maximum extent, and the removal rate of the total nitrogen is increased; and the leachate is treated by using mineralized refuses, so that the aim of treating wastes by using wastes is achieved.