A flip cover device is provided and includes a cover, a main body and a hinge. The hinge is disposed on the main body and pivotally connected to the cover in a detachable manner for allowing the cover to pivotally unfold relative to the main body. The hinge includes a hinge body and a notch structure formed on the hinge body. The cover abuts against the main body when the cover pivotally unfolds relative to the main body to an unfolded position along a first pivoting direction. When the cover is located at the unfolded position and forced by a torque along the first pivoting direction, the cover is driven by a reaction force provided by the main body to disengage from the hinge, which prevents a damage of the cover caused by an improper and excessive pivotal movement of the cover. Besides, a related hinge is further provided.