The invention provides an inner and outer plastic wrapping prefabricated underground barn. The inner and outer plastic wrapping prefabricated underground barn comprises a barn bottom, multiple prefabricated barn wallboards, a barn top and multifunctional columns. The barn wallboards are of overall structures formed by inner plastic plates, outer plastic plates and concrete plates between the inner plastic plates and the outer plastic plates, connecting devices are arranged on the peripheries of the barn wallboards, and the barn wallboards can be connected with the adjacent barn wallboards and the multifunctional columns through the connecting devices. The multifunctional columns are wrapped by plastic plates, the barn wallboards can be positioned, the depth of the portions, anchored into soil, of the multifunctional columns is larger than the depth of the barn bottom, and the multifunctional columns are main force bearing components for bearing soil pressure and grain side pressure and resisting buoyancy. The barn is characterized in that the multifunctional columns are divided into multiple segments from top to bottom, a first barn wallboard layer is arranged on the inner side of the first section of the uppermost layer, a second barn wallboard layer is arranged on the inner side of the second section till the lowest barn wallboard layer by means of the similar arrangement mode, and then the assembled underground barn structure is formed.