Protection control system and method for diesel engine starting and excavating machine

The invention relates to a protection control system and method for diesel engine starting and an excavating machine. The protection control system comprises a switch, a controller, a first relay and a starter. The controller is configured to send a control signal to the first relay and receive a feedback signal sent by the first relay. The controller is configured to control the first relay to be turned off and judge whether the first relay has a feedback signal or not after the switch is triggered. If the first relay does not have a feedback signal, it is judged that the first relay does not act, and a warning signal that the first relay has a fault is sent out. If the first relay has a feedback signal, whether the starter acts or not continues to be judged, if the starter does not act, a warning signal that the starter has a fault is sent out, and if the starter acts, a normal state signal is sent out. The starting state of a diesel engine can be fed back in real time, possible starting faults are judged i