Three-dimensional multi-wall plastic hollow box

The invention relates to a three-dimensional multi-wall plastic hollow box. The hollow box is characterized by comprising an oil tank body, wherein the oil tank body comprises an oil tank outer wall, an oil tank middle wall and an oil tank inner wall from outside to inside in sequence; a three-dimensional cavity structure is arranged in the oil tank body. The entire technical scheme is novel in design; a functional wall layer is increased in the production process of the oil tank for the first time; the three-dimensional structure with cavities on local parts of the oil tank body is formed through the oil tank outer wall, the oil tank middle wall and the oil tank inner wall, and the rigidity of the oil tank body is improved; during production and machining of the three-dimensional cavity structure, the cavity structure is formed when the functional wall layer is welded with the oil tank inner wall and the oil tank outer wall since the functional wall layer is arranged and is also named as the oil tank middle wall layer; the three-dimensional structure with the cavities on the local parts guarantees the connection performance of the inner wall and the outer wall of an oil tank shell and the rigidity of the oil tank body is improved.