The present invention discloses an autonomous robot, and a device and method for fault detection, belonging to the robot field. The method comprises: when trigger signals of a sensor is continuously received, the sensor is determined as a sensor to be detected; the autonomous robot is controlled to move and is controlled to rotate after the movement of the autonomous robot is end; and in the rotation process, if the trigger signals of the sensor to be detected is continuously received, it is determined the sensor to be detected has faults. Through controlling the movement of the autonomous robot and the rotation of the autonomous robot after the movement, the possibility that the autonomous robot continuously triggers signals at an original position caused by the environment where the autonomous robot is located; and moreover, in the rotation process, the state of the sensor to be detected at each direction is fully detected to determine whether there are faults of the sensor to be detected or not so as to improve the work reliability and the safety of a cleaning robot.