The invention relates to the technical field of
building construction, and discloses a deep foundation pit inner support dismantling device and a using method.The deep foundation pit inner support dismantling device comprises a bottom plate, universal wheels are rotationally installed at the bottom of the bottom plate, a
cutting device and a positioning device are arranged at the top of the bottom plate, and the
cutting device comprises a shell, a supporting table, a rotating motor, a rotating shaft, a first baffle and a saw blade; the positioning device comprises a rack, a gear, a driving shaft, a rotating seat and a
rotating disc, and further comprises an adjusting device and a protection device. According to the device, by adjusting the
cutting speed and the
operation mode, the fret saw can ensure that the cutting face is smooth and the size is accurate, the positioning device can accurately adjust the position and angle of the saw blade, the cutting precision is further improved, and through positioning of the gear rack and the
rotating disc, the position of the dismounting device can be adjusted in the displacement state of the bottom plate part; when the ground of a construction site is not enough to support the device to continuously move, normal cutting of the device is guaranteed, and the practicability of the device is improved.