The invention belongs to the field of construction, and particularly relates to a supporting structure and a supporting method for a foundation pit. The supporting structure for the foundation pit comprises double-row piles arranged on the periphery of the foundation pit, an anchor rod assembly and a reinforced soil body, a reinforced area is defined by the double-row piles, the double-row piles are anchored inside the ground of the foundation pit through the anchor rod assembly, and the reinforced soil body is formed in the reinforced area. The technical scheme that the reinforced soil body is arranged in the reinforced area inside the double-row piles is adopted, the integral supporting strength of the double-row piles is improved, the stability of the supporting structure for the foundation pit is guaranteed, the foundation pit is prevented from collapsing, and the problems such as potential safety hazards are solved.