The invention relates to a detection and protection circuit of an elevator door lock, comprising an elevator control panel, a running contactor, a brake contactor, a detection relay and a switch series circuit, wherein the switch series circuit comprises a plurality of detection switch blocks connected in series, and each detection switch block is connected to a gate switch circuit detection point in the elevator control panel. The detection and protection circuit of the elevator door lock is characterized in that the detection relay comprises at least a plurality of normally closed contacts and normally open contacts, and the first end of the switch series circuit is connected to an AC power live wire, and the second end is connected to the gate switch circuit detection point used for detecting the on-off of the switch series circuit in the elevator control panel, the running contactor and the brake contactor; at the same time, the connection point between every two adjacent detection switch blocks in the switch series circuit is connected to the AC power live wire through the normally open contacts. The circuit has the advantages of simple structure and high safety and reliability, so that elevator accidents can be reduced effectively.