The invention discloses a stereoscopic booster type vacuum preloading treatment method. The method comprises the steps that A, a preloading pit is excavated; B, inflation systems are pre-buried in the preloading pit and comprise the bottom inflation system and the lateral inflation system, inflation pipes of the bottom inflation system comprise the bottom inflation pipe pre-buried at the bottom of the preloading pit and the vertical inflation pipes connected with an inflation device outside the preloading pit in a vertically upward manner, and the lateral inflation system comprises lateral inflation pipes connected with the inflation device; C, soil needing to be subjected to vacuum preloading treatment is conveyed into the preloading pit, drainage plates are buried, and the soil is covered with sealing cloth; D, a pump drainage device is started, so that the drainage plates draw water in the soil till the pump drainage water amount is obviously reduced; and E, the inflation device is started, so that the bottom inflation pipe inflates the soil upwards, and the inflation device is started to laterally inflate the soil through the lateral inflation pipes. According to the treatment method, the soil can be inflated from the bottom upwards when the pump drainage effect of the drainage plates is greatly reduced, and the periphery of each drainage plate is inflated correspondingly, so that the water is extruded and centralized in the drainage plates, and the drainage effect is enhanced.