The invention relates to a method for building a road by pressing and silting large-scale silt sand on thick hydraulic filler, belonging to the technical field of soft foundation processing. The method process sequentially comprises: paving wattleanddaub and geotextile soft rows on the hydraulic filler, filling silt sand in filling bags to form a silt sand filling bag layer, drilling water drainage boards from the upper surface of the silt sand filling bag layer downwards, filling two layers of medium and coarse sand filling bags in the silt sand filling bag layer, paving a geotextile inverted filtering layer on the layers of medium and coarse sand filling bags, piling up road shoulders on the geotextile at two sides on the layers of medium and coarse sand filling bags, filling and pavingmacadam between two road shoulders and grinding with mountain crust soil repeatedly, and then spreading and paving clay-bound macadam on stones and mountain crust soil layer to finally form a road pavement. The invention has the advantages of fast construction speed, easy control of construction, abundant material source and cost saving.