Fabricated adjustable supporting device for foundation pit

The invention provides an assembly type foundation pit adjustable supporting device. Concrete baffles are connected through a connecting piece A and a connecting piece B, the connecting piece A is connected with one end of an adjustable supporting column through a reinforcing rib supporting column A, the other end of the adjustable supporting column is connected with a steel pipe through a reinforcing rib supporting column B, and the steel pipe is welded to a top supporting steel pipe A and a top supporting steel pipe B. Two sets of top supporting steel pipes A and top supporting steel pipes B are mutually welded to form a quadrilateral supporting body, four adjustable supporting column reinforcing rods are evenly arranged on the sides, close to the ends of the steel pipes, of the adjustable supporting columns in the circumferential direction, the inclined side faces of one ends of the adjustable supporting column reinforcing rods are welded to the adjustable supporting column outer movable rods, and the incl