Elevator cage door fault detection method, fault detection device and elevator

The invention provides an elevator cage door fault detection method and device and an elevator. The fault detection method comprises the steps that an opening and closing instruction is received, and a cage door lifting mechanism is controlled to execute the opening and closing instruction; the real-time torque of a driving motor in the cage door lifting mechanism is detected; determining whether the elevator cage door has an operation fault according to the real-time torque; and under the condition that the elevator cage door has the operation fault, the cage door lifting mechanism is controlled to stop executing the opening and closing instruction. After the cage door lifting mechanism starts to start and executes the opening and closing instruction, the real-time torque of the driving motor can be detected, and whether the elevator cage door is stuck or not can be judged according to the real-time torque, so that automatic identification of the stuck fault of the elevator cage door is realized; in addition