Combined double-row pile supporting system and construction method thereof

Provided are a combined double-row pile supporting system and a construction method thereof. The supporting system comprises front row piles, a front row pile top beam, rear row piles, a rear row pile top beam and a connecting beam. The front row beams are a row of reinforced concrete piles which are arranged at intervals in parallel. The rear row beams form a steel cement mixing pile wall, and the connecting beam is a double-limb connecting beam. Inward-inserting type steel in the steel cement mixing pile wall is H-shaped steel, and the upper end of the H-shaped steel is exposed out of the upper portion of the rear row pile top beam. Shallow layer reinforcing cement soil piles are further arranged between the front row piles and the rear row piles, and the shallow layer reinforcing cement soil piles and the steel cement mixing pile wall are overall in lap joint. The combined double-row pile supporting system overcomes the defect that a waterproof curtain needs to be additionally arranged in a common double-r