Dewatering treatment method for steeply inclined strip-shaped interbed composite stratum foundation pit

The invention discloses a dewatering treatment method for a steeply inclined strip-shaped interbed composite stratum foundation pit. The dewatering treatment method is characterized in that an open-cut hall shallow pit is included, an open-cut hall deep pit is included, a station shallow pit is included, a deep shallow pit boundary is included, an end well deep pit area is included, a rail-crossing cable deepening area is included, a water collection pit is included, an underground diaphragm wall is included, inner limestone fracture grouting is carried out, wall bottom limestone fracture grouting is carried out, a pressure reduction well is included, a drainage well is included, a confined water observation well serving as an emergency recharge well is included, and a down-turning beam pit groove is included. The dewatering treatment method is particularly suitable for underground water treatment of the composite stratum foundation pit with upper old city miscellaneous fill, middle hard plastic clay and lowe