Rectangular member overturning clamp with self-locking device

The invention discloses a rectangular member overturning clamp with a self-locking device. The rectangular member overturning clamp comprises an L-shaped hook I and an L-shaped hook II, wherein the L-shaped hook I and the L-shaped hook II are semi-closed in the periphery of a box column, a fixing hole I is formed in the L-shaped hook I, a fixing hole II is formed in the L-shaped hook II, the fixing hole I and the fixing hole II are fixed through a shackle, a pin hole I is formed in the lower-right corner of the fixing hole I in the L-shaped hook I, a pin hole II is formed in the lower-right corner of the fixing hole II in the L-shaped hook II, and the pin hole I and the pin hole II are matched with each other and locked through a pin roll. The rectangular member overturning clamp has the advantages of being suitable for various occasions, being flexible in application, having a self-locking function, and preventing the hooks from loosening in an overturning process to cause accidents.