Basement outer wall post-cast strip area fat groove backfilling method and soil retaining cofferdam operation well

The invention discloses a basement exterior wall post-cast strip area fat groove backfilling method and a soil retaining cofferdam operation well. The fat groove backfilling soil retaining cofferdam operation well comprises vertical keels which are arranged on the sides, where fat grooves are located, of basement exterior walls on the two sides of a post-cast strip area in the vertical direction; the multiple arched keels are horizontally arranged on the two vertical keels at intervals in the longitudinal direction of basement outer walls on the two sides of a post-cast strip area, the arched enclosure plates are arranged on the outer surfaces of the arched keels in a wrapping mode, and the ladder rods are parallel to the basement outer walls, close to the two ends of the arched keels and connected to the arched keels. And the ladder rods form a ladder for climbing. The device is simple in structure, safe, reliable, high in disassembly and assembly efficiency, short in period and capable of being recycled and