Deep foundation pit supporting structure

The invention belongs to the technical field of deep pit supporting, and particularly relates to a deep foundation pit supporting structure which comprises a moving trolley, a C-shaped soft plate and a sliding arm which are arranged on the outer side surface of the top of the moving trolley, a reinforcement cage movably connected to the inner side wall face of the output end of the sliding arm in a sleeving mode, and a protective cylinder movably connected to the inner side wall face of the C-shaped soft plate in a sleeving mode. Motor rotating shafts are symmetrically and fixedly installed on the outer side surface of the top of the moving trolley and located on the edges of the two sides, and two sets of lifters are fixedly installed at the output ends of the motor rotating shafts. The movable trolley is moved to the position where piling is needed, a pile casing is fixed through a C-shaped soft plate at the output end of a first elevator, one end of the pile casing penetrates through a limiting groove hole