The invention discloses a loose-proof adjustable two-dimensional connecting part. The loose-proof adjustable two-dimensional connecting part comprises two pedestals and a clamping plate; the upper surface of each pedestal is provided with a first sliding chute; the inner wall of each first sliding chute is slidably connected with a slider; the upper surface of each slider is fixedly connected witha supporting plate; the quantity of the supporting plates is 2; the opposite surfaces of the two supporting plates are correspondingly fixedly connected with a first movable plate and a second movable plate; the first movable plate is positioned at the left side of the second movable plate; the lower surface of the clamping plate is provided with a second sliding chute; the two ends of the secondsliding chute correspondingly communicate with the two sides of the clamping plate; and the first movable plate and the second movable plate are both slidably connected to the inner wall of the second sliding chute. By being provided with the first sliding chutes, the sliders, the first movable plate, the second movable plate and the second sliding chute, the loose-proof adjustable two-dimensional connecting part disclosed by the invention solves the problems that most of two-dimensional connecting parts in the present market are fixed in shape and size, are only connected with channel steelwhich is matched with the two-dimensional connecting parts in shape and size and are limited in use.