The invention discloses a method for preventing drop and hoisting of a single hanging ring. The method comprises the steps that a, a drop preventing mechanism of a
system for preventing drop and hoisting of the single hanging ring is opened and made to be in an unlocking state; b, when one of the hanging rings is mounted in the position, on one side of an
elevator, of a lug hole of a lifting lug, an induction part of a drop preventing part sends a
signal, after receiving the
signal, a controller forbids moving of a runner wagon, the runner wagon is in a stop state, and after the hanging ring enters the lug hole, the drop preventing mechanism is in a locking state, and the hanging ring is blocked in the lug hole; and c, and the other hanging ring is mounted in the position, on the other side of the
elevator, inside the lug hole of the lifting lug, the induction part of the drop preventing part sends a
signal, and after receiving the signal, the controller allows the runner wagon to move. It can be effectively guaranteed that the two hanging rings both enter the lug hole, so that single hanging ring hoisting is avoided. Through the joint effect of the drop preventing mechanism and the drop preventing part, the hanging rings can be blocked firmly in the lug hole, slipping is avoided, the working stability and reliability of the
elevator are improved, and the safety accident is eradicated.