The invention relates to a vacuum preloading solidification drainage construction method. Adopted drainage channels comprise a plurality of upper drainage pipelines and a lower drainage pipeline, the adjacent drainage pipelines are connected in a sealed mode, and holes used for drawing water are formed in the lower drainage pipeline. The construction method comprises the steps that a cushion layer is laid on a sludge layer on site, and a thin film is laid on the cushion layer; the first lowermost upper drainage pipeline of the drainage channels is connected with the lower drainage pipeline in a sealed mode, pipe shoes are arranged, the pipelines are vertically inserted into a hole of the thin film to reach the height allowing to be connected with the next pipeline conveniently, and it is guaranteed that the whole drainage pipelines are vertical; the second upper drainage pipeline and the first upper drainage pipeline are connected in a sealed mode; pipe inserting continues to be carried out, and the other upper drainage pipelines continue to be connected in a sealed mode until the depth required by the design is met; the upper drainage pipeline at the upper end and a water filter pipe are connected, and water drainage is carried out through a vacuum pump combined with negative pressure. According to the method, water drainage solidification can be carried out a soft foundation with the high water content, and the problem that horizontal bending deformation happens to a drainage plate in the drainage construction process can be effectively solved.