Building jacking

The utility model relates to the technical field of building instruments, in particular to a building jacking which comprises a lead screw, an adjusting nut is connected to the lead screw in a threaded mode, an upper support is fixed to the top of the lead screw, opposite clamping plates are arranged on the bottom face of the upper support, adjustable clamping mechanisms are arranged on the two sides of each clamping plate, and the adjustable clamping mechanisms and a rotary valve are arranged. A first screw rod is driven to rotate, meanwhile, the first screw rod transversely moves in a threaded pipe, the effect of adjusting the size of the clamping space is achieved, an adjustable clamping mechanism is arranged, a rotating valve is rotated, a second screw rod is driven to rotate, a nut seat on the second screw rod drives a clamping plate to transversely move, and opposite threads at the two ends are arranged, so that the clamping space is adjusted. Therefore, the clamping parts on the two transverse sides ca