Fabricated foundation pit support structure and construction method thereof

The invention discloses a fabricated foundation pit enclosure structure. The structure comprises a waterproof curtain and supporting row piles, wherein the waterproof curtain and the supporting row piles jointly form a deep foundation pit closed fabricated enclosure system which integrates soil retaining and water stopping and is large in rigidity and high in bearing capacity; components for supporting the row piles are assembled on the construction site; after the foundation pit is used, the supporting row piles can be recycled for reutilization; the waterproof curtain is three-axis cement soil mixing piles, the supporting row piles are constructed through a resonance-free vibration hammer by means of a vibration sinking method, and the construction site is environmentally friendly and free of slurry pollution. The structure is advantaged in that defects of an existing row pile or underground diaphragm wall foundation pit support structure are overcome, and green development and industrial construction of de