Tool-free mounting device and LED display screen using same

The invention relates to a tool-free mounting device and an LED display screen using the same. The tool-free mounting device is characterized in that a third convex part, inserted into the movable part of a sleeve, on the outer wall of a first toothed column is positioned by a concave part in the convex guide part on the inner wall of the sleeve, a second toothed column is driven to rotate relative to the first toothed column to a preset position by using the guide effect of the oblique end face, which correspondingly contacts with a fourth convex part and is located in the guide part, of a second convex part and restoring force, generated when the movable part is inserted into the sleeve and presses a spring, to the second toothed column, and accordingly the fourth convex part is clamped into a bayonet formed in the lower end face of the guide part so as to position the movable part in the sleeve, and other structures similarly drive the second toothed column to rotate until the movable part can be taken out