A method for relay diagnosis characterized by comprising: transmitting a control signal to the relay, wherein types of the control signal comprise an enable signal and a disable signal; applying a detection signal at one side of the relay, and receiving a feedback signal at the other side of the relay; and comparing the detection signal with the feedback signal to obtain a comparison result, wherein if the comparison result matches the control signal, the relay is determined as being normal, otherwise, the relay is determined as faulty, wherein if the comparison result matches the control signal, the relay is determined as being normal, otherwise, the relay is determined as faulty, comprises: if the comparison result is inconsistency and the control signal is the disable signal, then the comparison result matches the control signal and the relay is determined as being normal; if the comparison result is consistency and the control signal is the enable signal, then the comparison result matches the control signal and the relay is determined as being normal; if the comparison result is inconsistency and the control signal is the enable signal, then the comparison result does not match the control signal and the relay is determined as faulty; and if the comparison result is consistency and the control signal is the disable signal, then the comparison result does not match the control signal and the relay is determined as faulty. transmitting a control signal to the relay, wherein types of the control signal comprise an enable signal and a disable signal; applying a detection signal at one side of the relay, and receiving a feedback signal at the other side of the relay; and comparing the detection signal with the feedback signal to obtain a comparison result, wherein if the comparison result matches the control signal, the relay is determined as being normal, otherwise, the relay is determined as faulty, wherein if the comparison result matches the control signal, the relay is determined as being normal, otherwise, the relay is determined as faulty, comprises: if the comparison result is inconsistency and the control signal is the disable signal, then the comparison result matches the control signal and the relay is determined as being normal; if the comparison result is consistency and the control signal is the enable signal, then the comparison result matches the control signal and the relay is determined as being normal; if the comparison result is inconsistency and the control signal is the enable signal, then the comparison result does not match the control signal and the relay is determined as faulty; and if the comparison result is consistency and the control signal is the disable signal, then the comparison result does not match the control signal and the relay is determined as faulty. if the comparison result is inconsistency and the control signal is the disable signal, then the comparison result matches the control signal and the relay is determined as being normal; if the comparison result is consistency and the control signal is the enable signal, then the comparison result matches the control signal and the relay is determined as being normal; if the comparison result is inconsistency and the control signal is the enable signal, then the comparison result does not match the control signal and the relay is determined as faulty; and if the comparison result is consistency and the control signal is the disable signal, then the comparison result does not match the control signal and the relay is determined as faulty.