Abstract: The present invention provides a quick-setting nut, which uses two half connecting blocks linking together to form an integral nut by pivoting on a rivet at one side thereof and locking together with a half lap lock as a projection embedding in a recess between the interfaces thereof at other side of which. In practising, the unfolded present invention can be closed at a desired position on the long bolt, and with the aid of a slotted hole at one side of the pin joint portion sliding on the rivet, the inside threads of the nut can engage with or disengage from the long bolt for bolting up or removing.