Fly ash concrete piles are composed of fly ash, crushed stone, medium-coarse sand, and cement. When constructing fly ash concrete piles in soft soil areas using the bored grouting process, the concrete slump must reach 140-180 mm, and the maximum particle size of the crushed stone should be 1-3 cm. To ensure pile strength and reduce costs, 35%-45% medium-coarse sand is added as fine aggregate. Together with the soil between the piles, the fly ash piles form a composite foundation through the cushion layer laid over them. The improvement in bearing capacity is highly adjustable, settlement deformation is small, and the cost is low. The addition of fly ash gives the pile body significant later-stage strength. Owing to the relatively high strength of the pile body, higher bearing capacity can be achieved when used in soft soil foundations.