Vacuum preloading device with sandbag cushion layer, and construction method thereof

Disclosed are a vacuum preloading device with a sandbag cushion layer, and a construction method thereof. The vacuum preloading device comprises a vacuum pump, a vertical sandbag layer, a horizontal sandbag layer, geotextile, a clay sealing layer, a polyethylene sealing film and a split water sealing layer. The vertical sandbag layer, the horizontal sandbag layer, the geotextile, the clay sealinglayer, the polyethylene sealing film and the split water sealing layer are sequentially laid on the soil surface from bottom to top. A plurality of vacuum tubes communicated with the vacuum pump are embedded in sandbag gaps of the longitudinal sandbag layer, and a plurality of plastic drainage plates are fixedly inserted into the bottoms of sandbags of the vertical sandbag layer; the polyethylenesealing film is hermetically laid on the upper surfaces of the clay sealing layer and a film pressing groove; the split water sealing layer is arranged on the upper surface of the polyethylene sealingfilm. The vacuum preloadin