Pit-in-pit underground water treatment method for water-rich pebble stratum

The invention discloses a water-rich pebble stratum pit-in-pit underground water treatment method, and relates to the technical field of dewatering construction, and the method comprises the following steps: S1, occlusive piles are poured at the peripheries of a foundation raft sump and an elevator shaft pit to form a waterproof curtain, and a water suction pump position is reserved in the waterproof curtain; s2, a reinforced concrete water pressing plate is poured in a pit formed by the secant piles; s3, a water collecting pit and a slope side wall water pressing plate of the elevator shaft pit are installed and erected; s4, waterproof cloth is laid, a water suction pump is placed at the reserved position of the water suction pump, and graded broken stone is filled; and S5, finishing the construction of the cushion layer. The treatment method is simple in process, secant pile construction is conducted through each foundation pit, the problems that due to the fact that geology is uneven, a pit in a water-rich