The present invention relates to a composite of consolidation-hardening pile for soft ground and in which a composition ratio of an aggregate:a quicklime:an additive is 50-60 wt %:20-25 wt %:20-25 wt %, and the additive is an admixture made by mixing a powder of furnace slag, a fly ash or a mixture of the powder of furnace slag and the fly ash in a cement, the ratio of the cement, and the powder of furnace slag, the fly ash or the mixture of the powder of furnace slag aggregate and the fly ash is 65-85 wt %:15-35 wt %. As the pile is formed in the soft ground vertically, a composite has a strength of 50 kgf/cm² or over to act as a supporting pile for sinking, and a reinforcing pile.