The invention relates to a method for secondarily dehydrating bauxite direct floatation tailings, which effectively solves the problems that a press filter frame is easy to abrade, the thickness of a filter cake is non-uniform, the water content is high, the quality requirement cannot be met, and the cost is creased. The method comprises the following steps of carrying out the conventional examination on a box-typed diaphragm press filter, feeding, squeezing for the first time, blowing air for the first time, squeezing for the second time, blowing air for the second time, unloading the material and restoring. The method is simple in operation, direct and clear and easy to control; the thickness of the filter cake is uniform; the water content of the filter cake is low; the damage rate of a box-type diaphragm press filter frame is reduced, and the popularization value is high.